A spring coil embolization assist device

Abstract

This invention provides a coil embolization auxiliary device, belonging to the field of interventional medical device technology. The device includes a blocking unit and a delivery unit. The blocking unit has an inner stent and an outer stent arranged coaxially, with identical structures and capable of relative displacement. The delivery unit delivers the mesh-aligned inner and outer stents to the target position and drives relative displacement between them, causing the meshes of the inner and outer stents to overlap, at least reducing the overall mesh size at the blocking position of the blocking unit. This invention primarily addresses the technical contradiction of existing coil embolization auxiliary stents, where the mesh size needs to be adapted to the insertion of the microcatheter, making it difficult to simultaneously prevent coil dislodgement, while reducing the mesh size hinders microcatheter operation. It achieves the dual requirements of smooth microcatheter insertion and reliable coil blocking, improving the safety, efficiency, and therapeutic efficacy of wide-necked artery aneurysm embolization surgery.

Description

Technical Field

[0001] This invention belongs to the field of interventional medical device technology, specifically relating to a coil embolization auxiliary device. Background Technology

[0002] Intracranial aneurysms are a common cerebrovascular disease. Essentially, they are cystic protrusions formed by the impact of blood flow on a weakened localized wall of a cerebral artery. Rupture can lead to subarachnoid hemorrhage, resulting in extremely high rates of disability and mortality. Coil embolization, currently the mainstream minimally invasive treatment for intracranial aneurysms, involves inserting coils into the aneurysm cavity via a microcatheter. The mechanical packing action of the coils blocks the impact of blood flow on the aneurysm wall, promoting thrombus formation within the aneurysm and ultimately achieving a cure.

[0003] However, for wide-necked aneurysms (usually defined as a neck width ≥4mm or a neck / body ratio ≥0.5), simple coil embolization has significant limitations. Due to the wide aneurysm neck, the coils lack sufficient support and are prone to protruding into the parent artery from the neck. This not only affects the normal blood flow in the parent artery but may also lead to coil displacement and dislodgement, reducing embolization density and significantly increasing the aneurysm recurrence rate and the risk of re-rupture. To address this issue, a coil-assisted stent is typically placed at the aneurysm site to form a mechanical barrier at the aneurysm neck, preventing coil dislodgement.

[0004] Most existing coil-assisted stents are intracranial self-expanding stents, typically constructed from medical-grade stainless steel, cobalt-chromium alloy, or nickel-titanium alloy. The stent wall has numerous mesh openings, which are crucial for achieving the stent's assistive function. During surgery, the microcatheter must pass through the stent's mesh openings to enter the aneurysm cavity to deliver and pack the coils. Therefore, the mesh size must allow for smooth microcatheter insertion—generally, the mesh size should not be smaller than the microcatheter's outer diameter. Otherwise, the microcatheter may not be accurately positioned at the aneurysm opening, or it may become stuck or damaged while passing through the mesh, affecting surgical efficiency and safety.

[0005] However, the aforementioned mesh size, which meets the requirements for microcatheter insertion, has revealed significant drawbacks in long-term clinical application after surgery: due to the large mesh size, the coils are still at risk of dislodging from the mesh gaps into the parent artery due to factors such as blood flow impact and vascular pulsation within the aneurysm cavity. This risk is further increased when the coil packing density is low, the aneurysm shape is irregular, or postoperative vascular spasm or remodeling occurs. Once dislodged, it can lead to stenosis of the parent artery, thrombosis, or even re-inducing aneurysm rupture, seriously threatening the patient's life.

[0006] To reduce the risk of coil dislodgement, some studies have attempted to reduce the size of the stent mesh to enhance its blocking effect on the coils. However, reducing the mesh size raises new technical problems: on the one hand, excessively small meshes can obstruct the insertion of microcatheters, making it difficult for them to quickly and accurately pass through the mesh to reach the aneurysm sac, prolonging the operation time and increasing the risk of complications such as intraoperative vascular injury and excessive use of contrast agents; on the other hand, if the mesh size is close to or smaller than the outer diameter of the microcatheter, the microcatheter may be squeezed, deformed, or even unable to pass through the mesh, directly causing the coil packing operation to fail.

[0007] Therefore, a new type of spring coil auxiliary device is needed, which can achieve more reliable constraint on the spring coil without affecting the smooth passage of the microcatheter, thereby fundamentally solving the contradiction between operational convenience and long-term safety. Summary of the Invention

[0008] The purpose of this invention is to provide a coil embolization auxiliary device to solve the technical contradiction of existing coil embolization auxiliary stents, which is that "the mesh size needs to be adapted to the insertion of the microcatheter, but it is difficult to ensure the prevention of coil dislodgement. Reducing the mesh size will hinder the operation of the microcatheter." This invention achieves the dual requirements of smooth insertion of the microcatheter and reliable blocking by the coil, thereby improving the safety, efficiency and therapeutic effect of embolization surgery for wide-necked aneurysms.

[0009] To achieve the above objectives, the spring coil plug auxiliary device of the present invention provides the following technical solution: A spring coil plug auxiliary device includes a blocking unit and a conveying unit. The blocking unit has an inner support and an outer support arranged coaxially. The inner support and the outer support have the same structure and can undergo relative displacement. The conveying unit is used to convey the inner and outer supports with aligned meshes to the target position, and to drive the inner and outer supports to move relative to each other so that the meshes of the inner and outer supports overlap, at least to reduce the overall mesh size at the blocking position of the blocking unit.

[0010] As a further optimized technical solution, a water-soluble adhesive layer is arranged between the inner support and the outer support.

[0011] As a further optimized technical solution, a limiting structure is arranged between the inner support and the outer support to limit the distance of relative displacement between the inner support and the outer support.

[0012] As a further optimized technical solution, the limiting structure is a limiting wire, one end of which is fixedly connected to the far end of the outer support and the other end is fixedly connected to the far end of the inner support.

[0013] As a further optimized technical solution, the conveying unit includes: Delivery conduit; A pushing component is movably disposed within the lumen of a delivery conduit, and a stop unit is used to grip the distal end of the pushing component to deliver along the delivery conduit. A traction structure is movably disposed inside the pushing component, and is used to extend the pushing component to drive the inner support layer to move.

[0014] As a further optimized technical solution, the traction structure includes a traction wire, and a traction hook is provided at the distal end of the traction wire.

[0015] As a further optimized technical solution, the proximal end of the inner support is provided with a connection structure adapted to the traction hook.

[0016] As a further optimized technical solution, the connection structure is a snap-fit ​​hole, and the pull hook is used to snap into the snap-fit ​​hole to drive the inner support to move relative to the outer support.

[0017] As a further optimized technical solution, the locking holes are arranged symmetrically along the plane containing the axis of the inner layer support.

[0018] As a further optimized technical solution, the traction hook has two arms that are integrally fixedly connected and symmetrically arranged. The proximal ends of the two arms are fixedly connected to the traction wire, and the distal ends are arranged with hook-shaped structures that are adapted to the locking holes.

[0019] Beneficial effects: This invention, through the design of a double-layer coaxial stent structure with relative displacement, achieves dynamic adjustment of the overall mesh size of the blocking unit. In the early stage of surgery, the inner and outer stent meshes are aligned, and the blocking unit as a whole forms a larger mesh, ensuring that the microcatheter can smoothly pass through and extend into the aneurysm cavity to complete the coil packing. After packing, the delivery unit drives the relative displacement of the double-layer stent, causing the meshes to overlap and reduce the overall mesh size, effectively preventing the coil from dislodging. This fundamentally balances the contradiction between the convenience of microcatheter operation and the reliability of coil dislodging prevention, improving surgical safety and long-term efficacy.

[0020] Furthermore, the water-soluble adhesive layer ensures the relative fixation of the double-layer stent during delivery, preventing displacement that could affect positioning accuracy; the limiting structure limits the relative displacement distance, and the dimensions of the limiting structure are determined during processing, avoiding fine adjustments during surgical procedures, improving operational convenience, and enhancing the stability of the anti-dislodgement effect; the symmetrically arranged connecting structure, in conjunction with the traction hook, ensures balanced force on the inner stent, guarantees uniform mesh spacing, and improves the ease of adjustment. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the spring coil plug auxiliary device of the present invention; Figure 2 This is a three-dimensional structural diagram of the stopping unit in Embodiment 1 of the spring coil plug auxiliary device of the present invention; Figure 3 This is a schematic diagram of one end face of the stopping unit in Embodiment 1 of the spring coil plug auxiliary device of the present invention; Figure 4 This is a schematic diagram of the relative movement state of the inner and outer supports in Embodiment 1 of the spring coil embolization auxiliary device of the present invention; Figure 5 This is a schematic diagram of the inner and outer supports after relative movement in Embodiment 1 of the spring coil embolization auxiliary device of the present invention; Figure 6 This is a schematic diagram of one end face of the stopping unit in Embodiment 2 of the spring coil plug auxiliary device of the present invention; Figure 7 This is a schematic diagram of the relative movement state of the inner and outer supports of Embodiment 2 of the spring coil embolization auxiliary device of the present invention; Figure 8 This is a schematic diagram of the inner and outer supports after relative movement in Embodiment 2 of the spring coil embolization auxiliary device of the present invention.

[0022] In the diagram: 100, inner support; 110, connecting structure; 200, outer support; 300, limiting structure; 400, delivery conduit; 500, pushing component; 510, supporting structure; 600, pulling structure; 610, pulling wire; 620, pulling hook; 621, support arm; 622, hook-shaped structure. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0024] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. Furthermore, the term "proximal end" uniformly refers to the end closer to the operator, while "distal end" refers to the end farther from the operator.

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0026] The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions of the product; they are only intended to illustrate the content of the invention.

[0027] To address the technical contradiction in existing spring coil embolization devices where the mesh size cannot simultaneously balance the ease of microcatheter insertion and the reliability of preventing spring coil dislodgement, this invention provides a spring coil embolization auxiliary device. This device includes a blocking unit and a delivery unit. The blocking unit has an inner support 100 and an outer support 200 that are coaxially fitted, structurally identical, and capable of relative displacement. The mesh diameter of the inner support 100 and the outer support 200 is between 1mm and 2mm, accommodating the passage of the spring coil microcatheter. Both the inner support 100 and the outer support 200 have sinusoidal mesh shapes, improving the support's resistance to bending and its adherence to the wall. The delivery unit transports the blocking unit to the target position and drives the relative displacement of the two supports, causing their meshes to overlap and reduce the overall mesh size. A water-soluble adhesive layer is provided between the inner support 100 and the outer support 200 to ensure the relative stability of the two supports during delivery. A limiting structure 300 is provided between the inner stent 100 and the outer stent 200 to limit the relative displacement of the inner stent 100 and the outer stent 200. The delivery unit includes a delivery catheter 400, a pushing component 500, and a traction structure 600. The traction structure 600 is adapted to the connection structure 110 at the proximal end of the inner stent 100 to achieve precise driving. This invention can dynamically adjust the mesh size. In the early stage of surgery, the mesh is aligned to facilitate microcatheter operation. After packing, the staggered mesh prevents the spring coil from dislodging. It combines operational precision, safety, and versatility, and is suitable for intracranial wide-necked artery aneurysm embolization surgery, which can significantly improve surgical efficacy and long-term safety.

[0028] Example 1 like Figure 1 , Figure 2 , Figure 3 As shown, the spring coil plug auxiliary device includes a blocking unit and a conveying unit.

[0029] The blocking unit comprises an inner support 100 and an outer support 200. Both the inner and outer supports 100 are laser-cut from nickel-titanium alloy tubes, with smooth inner and outer walls and identical structures and shapes. Specifically, the mesh diameter of the inner support 100 and the outer support 200 is between 1mm and 2mm, accommodating the passage of the spring coil microcatheter. The meshes of both the inner and outer supports 100 are sinusoidal, improving their bending resistance and wall adhesion. The difference lies in the matching outer diameter of the nickel-titanium alloy tube used to process the inner support 100 with the inner diameter used to process the outer support 200, allowing them to be coaxially and fitted together. In the initial state, the inner stent 100 and outer stent 200 are coaxially attached with perfectly aligned meshes. At this point, the mesh size of the stopping unit is the same as that of the inner stent 100 and outer stent 200, thus the overall mesh size meets the passage requirements of commonly used clinical microcatheters. To further ensure the stability of the stopping unit during delivery, a water-soluble adhesive layer can be coated between the inner stent 100 and outer stent 200. This adhesive layer is made of medical-grade water-soluble polymer material, which can firmly bond the two stents in a dry environment and completely dissolves within 3-5 minutes upon contact with blood. This ensures that the relative displacement of the inner stent 100 and outer stent 200 can be directly manipulated after the coils are delivered.

[0030] After the spring coil is placed, the position between the inner stent 100 and the outer stent 200 can be moved relative to each other so that the mesh of the inner stent 100 and the outer stent 200 overlaps. In this embodiment, the inner stent 100 is pulled by the delivery unit described below, so that the inner stent 100 moves axially towards the proximal end relative to the outer stent 200. In this way, the distal end of the inner stent 100 overlaps with the proximal end of the outer stent 200, forming an effective blocking position for the aneurysm. Because the mesh of the inner stent 100 and the outer stent 200 overlaps at this position, the overall mesh size of the blocking position of the overall blocking unit can be reduced, thereby ensuring that the blocking unit effectively blocks the spring coil.

[0031] Furthermore, in order to facilitate the movement of the inner support 100, a locking hole is arranged at the near end of the inner support 100 as a connecting structure 110. In this embodiment, the locking holes are symmetrically arranged along the plane containing the axis of the inner support 100, so that the inner support 100 is subjected to balanced force and ensures the uniformity of the overlapping mesh.

[0032] Specifically, during the surgical procedure, it is not easy to move the inner stent 100 while ensuring that the position of the movement is such that the mesh of the inner stent 100 and the outer stent 200 overlap evenly and form the required blocking density. Furthermore, after adjusting the positions of the inner stent 100 and the outer stent 200, the two stents may shift again under the impact of blood flow. To improve the convenience of the operation and to ensure the stability of the two stents after displacement, a limiting wire is arranged between the inner stent 100 and the outer stent 200 as a limiting structure 300. Multiple limiting wires can be arranged at intervals along the circumference of the blocking unit, or only one can be arranged. One end of the limiting wire is fixedly connected to the distal end of the outer stent 200, and the other end is fixedly connected to the distal end of the inner stent 100. In this way, as... Figure 4 As shown, after the inner support 100 is displaced by pulling, the limiting wire is gradually tightened. Once the limiting wire is tightened, it provides mechanical feedback to the operator, preventing further displacement of the inner support 100. Alternatively, if the limiting wire is made of a reproducible material, the operator can determine the degree of straightening by observing the degree of bending. As long as the limiting wire is straightened, it can be concluded that the inner support 100 and the outer support 200 have moved to the required position. The length of the limiting wire is determined during the design and manufacturing of the stop unit, effectively reducing the operational difficulty during the process.

[0033] The delivery unit specifically includes a delivery catheter 400, a pushing component 500, and a traction structure 600. The pushing component 500 is movably disposed within the lumen of the delivery catheter 400, and a blocking unit is pressed against the distal end of the pushing component 500 to deliver the aneurysm along the delivery catheter 400 to the location of the aneurysm-bearing artery. In this embodiment, a balloon or silicone tube is provided at the distal end of the pushing component 500 at the position where the blocking unit is pressed, serving as a support structure 510 to support the blocking unit and provide a large frictional force to drive the blocking unit to move. Preferably, the support structure 510 is a balloon, which can be inflated after the blocking unit is released to further massage the blocking unit, ensuring that the blocking unit fully conforms to the target location.

[0034] The traction structure 600 is movably disposed inside the pusher 500 and is used to extend the pusher 500 after the spring coil is filled to pull the inner layer support 100 and drive it to move relative to the outer layer support 200.

[0035] Specifically, the traction structure 600 includes a traction wire 610, and a traction hook 620 is provided at the distal end of the traction wire 610. The traction wire 610 is made of a high-strength, low-creep medical alloy material, which can accurately transmit traction force.

[0036] The pull hook 620 has two integrally connected, symmetrically arranged support arms 621. The proximal ends of the two support arms 621 are fixedly connected to the pull wire 610, and the distal ends are provided with hook-shaped structures 622 that are adapted to the engagement holes. The symmetrical support arm 621 structure can undergo elastic deformation. When inside the pushing component 500, the distance between the two support arms 621 is small to fit the cavity of the pushing component 500 and facilitate transportation. When transported to the target position, the pull hook 620 is pushed out by the pull wire 610, and the distance between the two support arms 621 gradually opens so that the distance between the two hook-shaped structures 622 is adapted to the two engagement holes.

[0037] The surgical procedure in this embodiment is as follows:

[0038] First, the blocking unit, held at the distal end of the pushing component 500, is delivered via the delivery catheter 400 to the parent artery corresponding to the wide-necked aneurysm. The blocking unit is released to allow it to initially self-expand and adhere to the vessel wall. Then, the balloon is inflated, supporting and massaging the blocking unit to ensure full adhesion to the vessel wall. During this process, the water-soluble adhesive layer gradually dissolves. At this point, the delivery unit can be withdrawn, and coil packing is then performed. Specifically, a microcatheter is inserted into the aneurysm cavity through the mesh aligned with the blocking unit to complete the coil packing operation. After the filling is completed, the water-soluble adhesive layer has fully dissolved. At this point, the conveying unit is transported to the target position again. Then, the pulling wire 610 of the pulling structure 600 pushes the pulling hook 620 out of the pushing component 500, so that the hook-shaped structure 622 engages in the locking hole of the inner support 100. The pulling wire 610 is pulled proximally, driving the inner support 100 to axially translate relative to the outer support 200 until the limiting wire is tensioned. At this point, the mesh of the inner support 100 and the outer support 200 overlaps and intersects to the designed position, such as... Figure 5 As shown, this effectively prevents the spring coil from coming out. Finally, by pushing the pusher 500 to the distal end, the cavity of the pusher 500 constrains the two support arms 621 to move closer to each other, thereby allowing the pull hook 620 to smoothly disengage from the locking hole.

[0039] Example 2 like Figure 6 , Figure 7 , Figure 8 As shown, the difference between this embodiment and Embodiment 1 is that the displacement of the inner support 100 relative to the outer support 200 is axial rotation, as detailed below: The inner support 100 and the outer support 200 are still nickel-titanium alloy cut supports with identical structures. In the initial state, the mesh is aligned, and the water-soluble adhesive layer is set in the same way as in Example 1. The limiting structure 300 is a nickel-titanium alloy limiting wire. One end of the limiting wire is fixed to the braided wire at the far end of the outer support 200, and the other end is fixed to the braided wire at the far end of the inner support 100. The length of the limiting wire is set to the arc length that adapts to the set rotation angle, so as to limit the maximum rotation angle of the inner support 100 relative to the outer support 200.

[0040] The surgical procedure in this embodiment is basically the same as in Embodiment 1, except for the mesh adjustment step: After the spring coils are packed, the traction hook 620 is engaged in the locking hole of the inner stent 100 by the traction wire 610. By rotating the traction wire 610 proximally, the inner stent 100 is rotated around the axial direction of the outer stent 200 until the limiting wire is tensioned, and the meshes of the inner stent 100 and the outer stent 200 overlap. At this time, the overall mesh size of the limiting unit is reduced, achieving the blocking effect on the spring coils. Rotational adjustment can make the mesh overlap more uniform, which is suitable for aneurysms with irregular neck morphology.

[0041] In summary, the coil embolization auxiliary device provided by this invention achieves dynamic adjustment of the mesh through the relative displacement of the double-layer stent, effectively solving the core technical contradictions of existing stents. At the same time, the multiple auxiliary structures improve the operational accuracy and safety, making it suitable for the treatment of different types of wide-necked aneurysms, significantly reducing the risk of coil dislodgement, improving surgical efficacy, and showing broad clinical application prospects.

[0042] It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are within the protection scope of the present invention.

Claims

1. A spring coil plug auxiliary device, characterized in that, It includes a blocking unit and a conveying unit. The blocking unit has an inner support (100) and an outer support (200) arranged coaxially. The inner support (100) and the outer support (200) have the same structure and can undergo relative displacement. The conveying unit is used to convey the inner support (100) and outer support (200) with aligned meshes to the target position, and to drive the inner support (100) and outer support (200) to undergo relative displacement so that the meshes of the inner support (100) and outer support (200) overlap, at least to reduce the overall mesh size at the blocking position of the blocking unit.

2. The spring coil plug auxiliary device according to claim 1, characterized in that, A water-soluble adhesive layer is arranged between the inner support (100) and the outer support (200).

3. The spring coil plug auxiliary device according to claim 1, characterized in that, A limiting structure (300) is arranged between the inner support (100) and the outer support (200) to limit the distance of relative displacement between the inner support (100) and the outer support (200).

4. The spring coil plug auxiliary device according to claim 3, characterized in that, The limiting structure (300) is a limiting wire, one end of which is fixedly connected to the far end of the outer support (200), and the other end is fixedly connected to the far end of the inner support (100).

5. The spring coil plug auxiliary device according to any one of claims 1-4, characterized in that, The conveying unit includes: Delivery conduit (400); A pushing component (500) is movably disposed within the lumen of a delivery conduit (400), and a stop unit is used to grip the distal end of the pushing component (500) to deliver along the delivery conduit (400). A traction structure (600) is movably disposed inside the pusher (500) for extending out of the pusher (500) to drive the inner support (100) to move.

6. The spring coil plug auxiliary device according to claim 5, characterized in that, The traction structure (600) includes a traction wire (610), and a traction hook (620) is provided at the distal end of the traction wire (610).

7. The spring coil plug auxiliary device according to claim 6, characterized in that, The proximal end of the inner support (100) is provided with a connection structure (110) adapted to the traction hook (620).

8. The spring coil plug auxiliary device according to claim 7, characterized in that, The connection structure (110) is a locking hole, and the pull hook (620) is used to engage in the locking hole to drive the inner support (100) to move relative to the outer support (200).

9. The spring coil plug auxiliary device according to claim 8, characterized in that, The locking holes are arranged symmetrically along the plane containing the axis of the inner support (100).

10. The spring coil plug auxiliary device according to claim 9, characterized in that, The pull hook (620) has two integrally fixedly connected and symmetrically arranged arms (621). The proximal ends of the two arms (621) are fixedly connected to the pull wire (610), and the distal ends are arranged with hook-shaped structures (622) that are adapted to the locking holes.

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