A spring coil

Abstract

This invention relates to the field of medical device technology, specifically to a spring coil. A spring coil includes: a first body, which is a flexible structure with gaps; and a second body, fitted into the gaps of the first body, wherein the highest point of the second body is not higher than the highest point of the first body, and the surface area ratio of the second body to the first body is 1:0.1-3. This invention provides a low-cost spring coil with low pushing friction.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a spring coil. Background Technology

[0002] Coil implants are used to occlude arteriovenous malformations and aneurysms, and are also commonly used for emergency vascular closure in cases of accidental bleeding during surgical procedures. The mechanism of action of coils is to reduce local blood flow velocity and promote thrombus formation, thereby achieving occlusion. In coil interventional procedures, under the guidance of DSA angiography and a guidewire, the operator first delivers the catheter into position, then inserts the coil from the catheter to the lesion site for dense embolization. Therefore, the embolic performance of the coil is crucial to the success of the procedure. Factors affecting the embolic performance of coils include: coil volume (length, diameter), flexibility, coil tertiary morphology, and material.

[0003] The main material of most commercially available spring coil products is an alloy of 92% platinum and 8% tungsten, such as the Stryker Target spring coil series and the Penumbra Ruby spring coil series. There are also products that modify the 92% platinum and 8% tungsten alloy with polymer fibers, such as the Boston Scientific Interlock series, which uses polyester fibers (i.e., fibers wrapped around the platinum-tungsten alloy) as a base. There are also products that incorporate biodegradable fibers PGLA / PGA into the platinum-tungsten alloy base, such as Medtronic's Concerto series and Micrus' Cerecyte series.

[0004] However, the aforementioned coils are merely modifications of platinum-tungsten alloy, with polymer fibers comprising less than 10% of the material. The main component of the coil remains platinum-tungsten alloy, resulting in higher costs. Furthermore, these modifications, fixed to the coil surface, increase friction during coil pushing. Alternatively, these modifications may be absorbable materials that, after degradation, fail to provide reliable and stable support. All of these factors can negatively impact the final surgical outcome. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of high cost and large pushing friction of the spring coil in the prior art, so as to provide a spring coil with low cost and low pushing friction.

[0006] To solve the above-mentioned technical problems, the present invention provides a spring coil, comprising:

[0007] The first body is a flexible structure with gaps;

[0008] The second body is fitted into the gap of the first body. The highest point of the second body is not higher than the highest point of the first body, and the ratio of the surface area of ​​the second body to that of the first body is 1:0.1-3.

[0009] Optionally, the size of the gap is in the range of 0.001 to 0.010 inches; the ratio of the surface area of ​​the second body to that of the first body is 1:0.5 to 1.5.

[0010] Optionally, the first body is a metal body, and the second body is a non-metal body.

[0011] Optionally, the metal body is a platinum-tungsten alloy precursor wire or a primary coil, wherein the diameter of the platinum-tungsten alloy precursor wire ranges from 0.00275 to 0.0050 inches, the size of the platinum-tungsten alloy primary coil ranges from 0.010 to 0.030 inches, and the gap size of the platinum-tungsten alloy primary coil ranges from 0.0025 to 0.0045 inches.

[0012] Optionally, the non-metallic body is a polymer fiber structure, which is a precursor filament or a primary loop, and the diameter of the polymer fiber precursor filament is in the range of 0.0025–0.0045 inches.

[0013] Optionally, the distal end of the spring coil is provided with an arc structure, the size of which ranges from 0.02 to 0.025 inches; the diameter of the proximal end of the first body is smaller than the diameter of the main body, which is 0.001 to 0.02 inches.

[0014] Optionally, the first body and the second body are fixed by a fixing structure.

[0015] Optionally, the fixing structure is at least one of an adhesive, a heat shrink tubing, or a fixing knot.

[0016] Optionally, at least one of the adhesive, heat shrink tubing, and fixing knot is provided along the axial direction of the spring coil.

[0017] Optionally, the polymer fiber structure is any one of polypropylene, nylon, polyester, or polytetrafluoroethylene.

[0018] The technical solution of this invention has the following advantages:

[0019] 1. The spring coil provided by this invention, since the second body is embedded in the gap of the first body and the highest point of the second body is not higher than the highest point of the first body, will not cause the overall product surface to be rough, reduce surface friction, and ensure the smooth performance of the spring coil during push-out, thus shortening the operation time; the surface area ratio of the second body to the first body is 1:0.1-3, that is, the second body accounts for up to 50%, and its softness and coagulation properties can quickly achieve dense embolization and thrombus formation, achieve the therapeutic purpose, and further reduce costs.

[0020] 2. The spring coil provided by the present invention has a first body gap size that is slightly smaller than the second body wire size. Through interference fit, it can achieve a better stable interlocking effect.

[0021] 3. The spring coil provided by the present invention has a distal arc structure, which makes it less likely for the spring coil to puncture the tumor wall or blood vessel wall, thus ensuring the surgical effect.

[0022] 4. The spring coil provided by the present invention has a diameter at the proximal end of the first body that is smaller than the diameter of the main body, which can reduce the gap with the core wire, ensure the connection between the release area and the main body, and ensure the release strength in clinical practice, thus preventing the spring coil from being pulled apart.

[0023] 5. The spring coil provided by the present invention has a polymer fiber structure of any one of polypropylene, nylon, polyester or polytetrafluoroethylene. It will not be absorbed after implantation and, like the metal body, can provide long-term support. It can stably form a basket in tumor filling and can be anchored in blood vessels to prevent it from being washed away. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the spring coil provided by the present invention before implantation into the human body;

[0026] Figure 2 A schematic diagram of the spring coil provided by the present invention after implantation in the human body;

[0027] Figure 3 This is a schematic diagram showing how a spring coil is fixed using heat shrink tubing.

[0028] Figure 4 This is a schematic diagram showing how a spring coil is fixed by a fixing knot.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. First body; 2. Second body; 3. Heat shrink tubing; 4. Fixing junction; 5. Anti-unwinding wire. Detailed Implementation

[0031] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] like Figures 1 to 2 In one specific embodiment of the spring coil shown, the end of the spring coil furthest from the operator during use is the distal end, and the end closest to the operator is the proximal end. When the spring coil is used for embolization of aneurysms or blood vessels, it needs a certain three-dimensional shape to form a stable basketing or anchoring effect. Therefore, the spring coil needs a certain three-dimensional shape, specifically including a first body 1 and a second body 2.

[0034] The first body 1 is a flexible structure with gaps, specifically a metal body, preferably made of a platinum 92% + tungsten 8% alloy to form the spring structure. Platinum is an inert metal with excellent biocompatibility and stability, allowing it to effectively promote thrombus formation without causing toxicological problems due to long-term implantation. The mechanism of spring coil packing at the site of aneurysm or vascular lesion is to promote thrombus formation at the lesion site, reduce blood impact on the fragile aneurysm wall, and prevent aneurysm rupture. In acute bleeding vessels or varicose veins, the spring coil can effectively block the bleeding or reduce blood flow in the vessel, thereby achieving the therapeutic purpose. Platinum-tungsten has excellent radiopaque properties. Coil embolization is an interventional treatment procedure, and radiopaque materials can better assist the operator in product positioning and a series of judgments during the procedure. The platinum spring structure has excellent flexibility, allowing the spring coil to form a dense thrombus during packing; secondly, the flexible material is less likely to damage the aneurysm wall or vessel wall, causing adverse phenomena such as vasospasm. The size of the gap ranges from 0.001 to 0.010 inches.

[0035] The metal body can be categorized into three forms: primary wire (first-level form), primary coil (second-level form), and two-dimensional or three-dimensional spring coil (third-level form). The primary coil (second-level form) involves winding the primary wire onto a fine mold. In this embodiment, the shaping of the platinum-tungsten alloy portion follows the traditional spring coil shaping process. During shaping, the platinum-tungsten alloy with gaps requires a third-level shaping (which can be two-dimensional or three-dimensional). In this embodiment, the metal body is a platinum-tungsten alloy primary wire or primary coil, preferably a primary coil. The diameter of the platinum-tungsten alloy primary wire ranges from 0.00275 to 0.0050 inches, the size of the platinum-tungsten alloy primary coil ranges from 0.010 to 0.030 inches, preferably 0.020 inches, and the gap size of the platinum-tungsten alloy primary coil ranges from 0.0025 to 0.0045 inches.

[0036] The second body 2 is fitted into the gap of the metal body, specifically a non-metallic body, such as a polymer fiber structure. The highest point of the polymer fiber structure is not higher than the highest point of the metal body, and the surface area ratio of the polymer fiber structure to the metal body is 1:0.1-3, preferably 1:0.5-1.5.

[0037] The polymer fiber structure is any one of polypropylene, nylon, polyester, or polytetrafluoroethylene. The soft material properties of the polymer fiber allow for dense embolization during packing, rapidly forming a thrombus; secondly, the soft material is less likely to damage the aneurysm wall or blood vessel wall, causing adverse effects such as vasospasm. The purpose of coil therapy is to reduce blood flow in the blood vessel and form a thrombus; the procoagulant properties of the polymer can improve the overall treatment efficiency of the coil. Traditional pure platinum is a precious metal and expensive; in this embodiment, the polymer fiber accounts for up to 50%, and the price of polymer fiber is much lower than that of platinum, thus resulting in a lower overall coil price.

[0038] The polymer fiber structure is a precursor filament or primary coil, preferably a precursor filament, with a diameter ranging from 0.0025 to 0.0045 inches. The polymer fiber structure can be single-stranded or multi-stranded, preferably single-stranded. The design of uniformly mixing the polymer fiber structure with the platinum metal body also plays a role in force transmission; the platinum metal can drive the flexible polymer fiber structure forward, achieving a proximal-to-distal force transmission efficiency of approximately 85%-95%. Three-dimensional coils are more stable than two-dimensional coils during packing, allowing for more stable basket formation and providing a reliable framework for subsequent filling and finishing coils, preventing puncture of the aneurysm wall. In vascular coil embolization, three-dimensional coils can be stably anchored in the blood vessel, preventing them from being washed away by high-speed blood flow and causing blockages in non-embolized areas, leading to a series of adverse clinical events. Furthermore, as... Figure 2As shown, the three-dimensional spring coil is easier to rotate at any time during filling. The polymer fiber structure is embedded in the metal body to form a whole, which ensures that the overall spring coil can rotate at any time during filling.

[0039] Furthermore, the polymer fiber structure can be further processed during extrusion as needed, such as drug loading treatment on the surface of the polymer fiber, coating the surface of the polymer fiber with drugs with anti-inflammatory effects to promote tissue endothelialization; microporous treatment on the surface of the polymer fiber, allowing the polymer fiber to swell with blood and make the embolism denser, etc.

[0040] The distal end of the spring coil has an arc-shaped structure, the size of which ranges from 0.02 to 0.025 inches. The arc-shaped structure is formed by dispensing UV-curable adhesive, which is biocompatible, stable, and has a smooth surface without hard protrusions. The amount of UV-curable adhesive used is 0.01 to 0.1 ml. The distal polymer fiber structure and the metal body are fixed by knotting or adhesive.

[0041] The diameter of the proximal end of the metal body is smaller than that of the main body, ranging from 0.001 to 0.02 inches, preferably 0.01 inches. The material is the same as that of the main body, being platinum-tungsten, which prevents micro-electrochemical corrosion, and it has a two-dimensional helical structure. The proximal polymer fiber structure and the metal body are fixed by knotting or adhesive.

[0042] Although both the platinum-tungsten alloy and the polymer fiber structure undergo heat setting treatment, their morphology has a certain degree of stability. However, the strength is insufficient to rely solely on the gaps in the platinum-tungsten alloy to interlock the polymer fiber structure. Especially since some polymers are inherently very smooth, such as polypropylene and polytetrafluoroethylene, the metal body and the polymer fiber structure are also fixed by a fixing structure. Specifically, the fixing structure is at least one of an adhesive, heat shrink tubing 3, or fixing knot 4, and at least one of the adhesive, heat shrink tubing 3, and fixing knot 4 is arranged along the axial direction of the spring coil, preferably multiple knots spaced apart.

[0043] When multiple spring coils are used, the specific method for fixing them with adhesive is as follows: UV-curable adhesive or other similar adhesive is applied every 0.2m along the axial direction of the spring coils to fix the polymer fiber structure and the metal body. Since the two have a certain degree of cohesion through the gaps, and the adhesive will increase the hardness to a certain extent, in order to ensure the overall flexibility after mixing, the interval between adhesive applications can be appropriately large. Preferably, there should be no more than 5 adhesive applications on a single spring coil.

[0044] like Figure 3As shown, when multiple heat shrink tubes are used, the specific method for fixing them is as follows: one heat shrink tube 3 is added every 0.2m along the axial direction of the spring coil to fix the polymer fiber structure and the metal body. Since the two have a certain degree of cohesion through the gap, and the heat shrink tube 3 will increase the hardness to a certain extent, in order to ensure the overall softness after mixing, the interval between two heat shrink tubes 3 can be appropriately large. Preferably, there should be no more than 5 heat shrink tubes 3 on one spring coil. And the length of each heat shrink tube 3 is recommended to be about 1-3mm. During processing, the mixed spring coil can be inserted into the heat shrink tube 3 in a secondary shape for heat shrinking. The wall thickness of the heat shrink tube 3 needs to be extremely thin to ensure the overall softness. Preferably, the wall thickness of the heat shrink tube 3 is 0.0002-0.0005 inches.

[0045] Many traditional spring coils contain one or two anti-unwinding threads 5. In this embodiment, an anti-unwinding thread 5 can also be added to the hybrid spring coil. The material can be polypropylene, POE, PET, etc., and the size range is 0.001-0.002 feet. Figure 4 As shown, the specific method for fixing using a fixed knot is as follows: An anti-unwinding wire 5 is inserted into the inner cavity of the secondary-shaped hybrid spring coil. Simultaneously, at intervals of 0.1-0.2m, the internal anti-unwinding wire 5 is extended to the outer surface of the hybrid spring coil and knotted. Since the anti-unwinding wire 5 is also made of a soft polymer material, the interval between the knots and the outer surface of the hybrid spring coil can be appropriately increased, preferably around 5-10 knots. The original gap at the knots can be appropriately widened for ease of operation.

[0046] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A spring coil, characterized in that, include: The first body (1) is a flexible structure with gaps; The second body (2) is fitted into the gap of the first body (1). The highest point of the second body (2) is not higher than the highest point of the first body (1), and the ratio of the surface area of ​​the second body (2) to that of the first body (1) is 1:0.1-3.

2. The spring coil according to claim 1, characterized in that, The size of the gap is in the range of 0.001 to 0.010 inches; the surface area ratio of the second body (2) to the first body (1) is 1:0.5 to 1.

5.

3. The spring coil according to claim 2, characterized in that, The first body (1) is a metal body, and the second body (2) is a non-metal body.

4. The spring coil according to claim 3, characterized in that, The metal body is a platinum-tungsten alloy precursor wire or a primary coil. The diameter of the platinum-tungsten alloy precursor wire ranges from 0.00275 to 0.0050 inches, the size of the platinum-tungsten alloy primary coil ranges from 0.010 to 0.030 inches, and the gap size of the platinum-tungsten alloy primary coil ranges from 0.0025 to 0.0045 inches.

5. The spring coil according to claim 4, characterized in that, The non-metallic body is a polymer fiber structure, which is a precursor fiber or a primary loop. The diameter of the polymer fiber precursor fiber ranges from 0.0025 to 0.0045 inches.

6. The spring coil according to any one of claims 1-5, characterized in that, The distal end of the spring coil has an arc structure with a size range of 0.02-0.025 inches; the diameter of the proximal end of the first body (1) is smaller than the diameter of the main body, and is 0.001-0.02 inches.

7. The spring coil according to any one of claims 1-4, characterized in that, The first body (1) and the second body (2) are fixed by a fixing structure.

8. The spring coil according to claim 7, characterized in that, The fixing structure is at least one of adhesive, heat shrink tubing (3) or fixing knot (4).

9. The spring coil according to claim 8, characterized in that, At least one of the adhesive, heat shrink tubing (3), and fixing knot (4) is provided along the axial direction of the spring coil.

10. The spring coil according to claim 5, characterized in that, The polymer fiber structure is any one of polypropylene, nylon, polyester, or polytetrafluoroethylene.

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