CN113951964B

CN113951964B - Embolic coil and coil system

Info

Publication number: CN113951964B
Application number: CN202111308229.8A
Authority: CN
Inventors: 王高波; 汤汉林
Original assignee: Juhui Medical Technology Shenzhen Co ltd
Current assignee: Juhui Medical Technology Shenzhen Co ltd
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2023-11-17
Anticipated expiration: 2041-11-05
Also published as: CN113951964A

Abstract

The application discloses an embolic spring ring and a spring ring system, wherein the embolic spring ring comprises a head structure and a spring body which extends spirally, the spring body is connected with the head structure, the head structure comprises at least two abutting pieces, the at least two abutting pieces are connected with the spring body, when the spring body is in a primary spiral state and the abutting pieces are naturally opened, the at least two abutting pieces form an included angle with the axis of the spring body, the included angle is smaller than or equal to 90 degrees, and the included angle is larger than 45 degrees.

Description

Embolic coil and coil system

Technical Field

The application relates to the technical field of medical instruments, in particular to an embolic coil and a coil system.

Background

This section provides merely background information related to the present disclosure and is not necessarily prior art.

In intracranial vascular diseases, intracranial aneurysms are saccular aneurysms formed by the outward expansion of local vascular walls due to structural dysplasia of the arterial walls in the brain or injury or aging of the arterial walls caused by cerebral trauma and arteriosclerosis. Intracranial aneurysms are extremely easy to break suddenly when the blood pressure of occasional tension, effort, fatigue and the like rises, the caused intracranial spiral subomental hemorrhage and serious complications caused by the intracranial spiral subomental hemorrhage have great threat to life and health of people, and the death rate and the disability rate are high.

There are two current methods of treating cerebral aneurysms: craniotomy clamp closure and minimally invasive interventions. Craniotomy and occlusion are the first treatments for cerebral aneurysms, where the vessel, including the segment and aneurysm, is exposed after craniotomy and then blocked at its root by a clip. However, because of the relatively large trauma, recovery time after surgery is completed is relatively long and there is a certain risk of surgery. The device can be used for the embolization treatment of the intravascular spring ring for patients with aneurysms, which are extremely high in risk of craniotomy, failed in craniotomy, unsuitable for craniotomy due to systemic and local conditions, and the like.

The other is intravascular interventional therapy, which is to use a femoral artery puncture to place a fine micro-catheter in an aneurysm sac or a tumor neck part through a DSA radiography technology, and then send a soft embolic spring ring into the aneurysm sac through the micro-catheter and fill the aneurysm sac so as to make the blood flow in the aneurysm sac disappear, thereby eliminating the risk of rupture and bleeding.

As shown in fig. 1, the existing embolic coil product mainly includes a delivery rod 11, a release mechanism 12 and an embolic coil 13, wherein the head end of the embolic coil 13 is fixed at the head end of the embolic coil 13 after being melted into a hemisphere by a polymer material, and when the embolic coil 13 is released from a microcatheter (not shown), the head end of the embolic coil 13 will first touch the wall of an aneurysm, and the risk of puncturing the aneurysm is threatened during operation due to the hardness of the head end bulb and small contact area, which threatens the life safety of a patient.

Disclosure of Invention

The object of the present application is to solve at least the problem of the easy puncture of an aneurysm when implanting a spring coil. The aim is achieved by the following technical scheme:

the embodiment of the application provides an embolic spring ring which is conveyed through a microcatheter, wherein the embolic spring ring comprises a head structure and a spring body which extends spirally, the spring body is connected with the head structure, the head structure comprises at least two abutting pieces, the at least two abutting pieces are connected with the spring body, when the spring body is in a primary spiral state and the abutting pieces are naturally opened, the at least two abutting pieces form an included angle with the axis of the spring body, and the included angle is smaller than or equal to 90 degrees and larger than 45 degrees.

Embodiments of the present application also provide a spring coil system comprising a microcatheter and an embolic spring coil as described above, the embolic spring coil being loaded into and delivered through the microcatheter.

When the embolic coil is implanted into the tumor cavity, at least two abutting pieces are all in an included angle a with the axis of the spring body, the included angle a is smaller than or equal to 90 degrees, and the included angle a is larger than 45 degrees, so that the abutting pieces are contacted with the tumor cavity wall before the spring body contacts the tumor cavity wall, the contact area of the embolic coil and the tumor cavity wall is increased, the pressure of the embolic coil on the tumor cavity wall is reduced, the tumor cavity is prevented from being punctured when the embolic coil is released, and the abutting pieces can be continuously elastically deformed when the abutting pieces are continuously pushed after being contacted with the tumor cavity wall, the abutting pieces are gradually increased in an included angle with the axis of the spring body, the abutting pieces can slide along the tumor cavity wall in the elastic deformation process, the contact area of the abutting pieces and the tumor cavity wall is further increased, the pressure of the tumor cavity wall is prevented from being excessively concentrated in the embolic coil release process, and the tumor cavity is prevented from being punctured.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

FIG. 1 is a schematic view of a prior art spring coil system;

FIG. 2 is a diagram illustrating an embodiment of the present application showing the embolic coil in a coil system in a compressed state;

FIG. 3 is a view showing the head structure of the spring coil system in an expanded state according to an embodiment of the present application;

FIG. 4 is a partial cross-sectional view of an embolic coil in an embodiment of the application;

FIG. 5 is a partial cross-sectional view of a head structure in accordance with one embodiment of the application;

FIG. 6 is a diagram showing the implantation of embolic coils in a tumor cavity in accordance with one embodiment of the present application;

FIG. 7 is an enlarged view of A in FIG. 6;

fig. 8 is a schematic structural view of a supporting plate according to an embodiment of the application.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, spatially relative terms, such as "inner," "outer," "lower," "below," "upper," "above," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein interpreted accordingly.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the present application, the end that is closer to the operator in use is referred to as "proximal end", the side that is relatively closer to the operator is referred to as "proximal end", the end that is far from the operator is referred to as "distal end", and the side that is relatively far from the operator is referred to as "distal end", and the "proximal end", "distal end", "proximal end", and "distal end" of any component of the blood flow guiding stent system are defined according to this principle.

As shown in fig. 2 and 3, the present embodiment provides a spring coil system 200 comprising a microcatheter 21 and embolic coils 23, the embolic coils 23 being loaded within the microcatheter 21 and delivered through the microcatheter 21.

The embolic coil 23 comprises a head structure 25 and a helically extending spring body 43, the distal end of the spring body 43 being connected to the head structure 25.

As shown in fig. 3 and 4, the spring body 43 is a spiral body formed by winding a platinum-tungsten alloy wire, and when the spring body 43 is in a secondary spiral state, the spring body is generally in an O shape or pi shape after the platinum-tungsten alloy wire is wound into a tubular primary spiral body and then the primary spiral body is further wound into a secondary spiral body. When the spring body 43 is loaded in the microcatheter 21, the spring body 43 is in a primary helical state, having an axial cavity 45. When the spring body 43 is completely released from the micro-catheter 21, the spring body 43 is deformed from the primary coil state to the secondary coil state.

As shown in fig. 4 and 5, the head structure 25 includes an inner retaining ring 27, an outer retaining ring 29. The outer fixing ring 29 and the inner fixing ring 27 are fixed to each other, the outer fixing ring 29 is sleeved outside the inner fixing ring 27, and the outer fixing ring 29 is fixedly inserted into the axial cavity 45 of the spring body 43, so that the head structure 25 is connected with the spring body 43.

Referring again to fig. 2, the head structure 25 further includes at least two abutment plates 31, the at least two abutment plates 31 are uniformly disposed along the circumferential direction of the spring body 43, and the at least two abutment plates 31 are fixedly connected with the inner fixing ring 27 and the outer fixing ring 29, so that the abutment plates 31 are connected with the spring body 43. In the present embodiment, the number of the contact pieces 31 is four. In other embodiments, the number of abutment pieces 31 may be two, three or more pieces.

The abutment 31 includes a plurality of wires 33, and the plurality of wires 33 may be knitting wires or wires cut by laser, and the abutment 31 in this embodiment is a knitting wire. The material of the wire 33 may be nickel-titanium alloy wire or other alloy wire with shape memory, or polymer wire. The wires 33 are interlaced with each other to form a mesh shape, so that the contact area of the abutment piece 31 when contacting the tumor cavity wall 61 (shown in fig. 7) can be increased, the pressure of the abutment piece 31 on the tumor cavity wall 61 can be reduced, and the abutment piece 31 can be prevented from puncturing the tumor cavity.

Referring to fig. 2 again, a section between the first end 35 and the second end 37 protrudes to one side to form a first protruding section 39, another section between the first protruding section 39 and the second end 37 protrudes to the other side to form a second protruding section 41, the protruding directions of the first protruding section 39 and the second protruding section 41 are opposite, when the embolic coil 23 is loaded on the micro-catheter 21 for transportation, the first protruding section abuts against the wall of the micro-catheter 21, and the second protruding section and the second end 37 keep a distance from the wall of the micro-catheter 21, so that friction between the abutting piece 31 and the inner wall of the micro-catheter 21 can be reduced, and resistance when the abutting piece 31 is pushed is reduced.

The second end 37 of the abutment 31 is deflected relative to the second projection 41 in a direction in which the first projection 39 projects, so that, when the embolic coil 23 is released, the relatively sharp second end 37 is prevented from being inserted into the tumor cavity wall 61, and the abutment 31 is guided to slide along the surface of the tumor cavity wall 61.

The structures of the abutment plates 31 in the present embodiment are substantially the same, except that the arrangement of the maximum width portions of the adjacent two abutment plates 31 is different. Specifically, in one embodiment, each abutment tab 31 has a location of maximum width between its two ends, the location of maximum width of adjacent two abutment tabs 31 being located in different radial planes of the microcatheter 21 when the embolic coil 23 is loaded in the microcatheter 21 for delivery. If the maximum width of all the contact pieces 31 are located in the same radial plane of the microcatheter 21, the contact pieces 31 will be too crowded with material in the radial plane, and the resistance will be increased during pushing. In this embodiment, the portions of the adjacent two abutment plates 31 with the largest width are located in different radial planes of the microcatheter 21, so that the pushing resistance of the abutment plates 31 can be reduced.

At least two of the abutment plates 31 are each coated with a coating film, such as a ptfe film, which can accelerate the increase in lubricity of the abutment plates 31 and the endothelialization.

Referring to fig. 2, 4 and 5, the abutment piece 31 includes a first end 35 connected to the spring body 43 and a second end 37 opposite to the first end 35. The wire heads of the abutment pieces 31 are gathered at the first end 35 and are fixed between the outer fixing ring 29 and the inner fixing ring 27 such that the abutment pieces 31 are connected to the spring body 43 by the outer fixing ring 29. The contact piece 31 has elasticity and can be elastically compressed to the microcatheter 21 for delivery.

Referring to fig. 3, in the present embodiment, the spring body 43 is in a primary spiral state, and when the abutting pieces 31 are naturally opened, at least two abutting pieces 31 form an included angle a with the axis of the spring body 43, the included angle a is smaller than or equal to 90 ° and the included angle a is larger than 45 °. That is, when the spring body 43 is loaded in the micro-catheter 21 and the abutment pieces 31 are released outside the micro-catheter 21 to be naturally opened, at least two abutment pieces 31 form an angle a with the axis of the spring body 43, the angle a is smaller than or equal to 90 °, and the angle a is larger than 45 °.

Referring to fig. 6 and 7, when the plug spring 23 is released in the tumor cavity, the abutment piece 31 contacts the tumor cavity wall 61 earlier than the spring body 43. Compared with the prior art that the distal end ball of the spring body 43 directly contacts the tumor cavity wall 61, the contact piece 31 in the embodiment is in surface contact with the tumor cavity wall 61 (the prior art is equivalent to point contact), so that the contact area of the embolic coil 23 and the tumor cavity wall 61 is increased, the pressure of the embolic coil 23 on the tumor cavity wall 61 is reduced, and the tumor cavity is prevented from being punctured when the embolic coil 23 is released. And, if the abutting piece 31 is pushed continuously after contacting with the tumor cavity wall 61, the abutting piece 31 can be deformed continuously, the included angle between the abutting piece 31 and the axis of the spring body 43 is increased gradually, the abutting piece 31 can slide along the tumor cavity wall 61 in the elastic deformation process, and the contact area between the abutting piece 31 and the tumor cavity wall 61 is further increased, so that the excessive concentration of the pressure to the tumor cavity wall 61 in the releasing process of the embolic coil 23 is avoided, and the puncture of the tumor cavity is avoided. It should be explained that the first end 35 projects a first ray formed on the abutting piece 31 at a position far away from the first end 35 and axially farthest from the most distal portion, and the axis of the spring body 43 is a second ray formed from the proximal end to the distal end, and the abutting piece 31 forms an included angle with the axis of the spring body 43 as the included angle formed by the first ray and the second ray together.

In addition, since the abutment piece 31 has a grid structure, the contact area between the abutment piece 31 and the tumor cavity wall 61 can be further increased, and the roughness of the abutment piece 31 can be increased, so that the endothelialization can be accelerated, and the effect of accelerating the treatment can be achieved.

In an embodiment, when the spring body 43 is in a primary spiral state and the abutment plates 31 are naturally opened, at least two abutment plates 31 form an included angle with the axis of the spring body 43, the included angle is less than or equal to 90 ° and the included angle is greater than or equal to 60 °, so that the abutment plates 31 can more conveniently slide along the tumor cavity wall 61 after contacting the tumor cavity wall 61, and the pressure of the abutment plates 31 on the tumor cavity wall 61 is reduced.

In this embodiment, the length of the abutment piece 31 is 3 to 5 times the outer diameter of the spring body 43, and the maximum width of the abutment piece 31 is 2 to 3 times the outer diameter of the spring body 43, so that the contact area between the abutment piece 31 and the tumor cavity wall 61 is far greater than that between the ball head and the tumor cavity wall 61 in the prior art, and compared with the prior art, the contact area between the embolic coil 23 and the tumor cavity wall 61 can be increased. In this embodiment, the "outer diameter of the spring body 43" refers to the outer diameter of the spring body 43 when it is in a first-stage spiral unless otherwise specified.

As shown in fig. 8, in one embodiment, the abutment piece 31 has an axial length L, and the knitting density of the abutment piece 31 in a region extending L/3 in the longitudinal direction thereof from the first end 35 toward the second end 37 is K1. The abutting piece 31 has a knitting density K2, K1 > K2 in a region extending L/3 from the second end 37 in the longitudinal direction thereof toward the first end 35, so that the abutting piece 31 has a smaller flexibility in a region extending L/3 from the first end 35 in the longitudinal direction thereof toward the second end 37 than in a region extending L/3 from the second end 37 in the longitudinal direction thereof toward the first end 35, that is, the abutting piece 31 has a larger flexibility at the second end 37 than at the first end 35. When the abutment piece 31 is in contact with the tumor cavity wall 61, the distal portion of the abutment piece 31 is in contact with the tumor cavity wall 61, and the distal portion of the abutment piece 31 is softer, so that the distal end of the abutment piece 31 can be further prevented from puncturing the tumor cavity wall 61. The knitting density refers to the number of meshes per unit area.

The knitting density of the abutment piece 31 in this embodiment is gradually reduced from the first end 35 to the second end 37.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. The utility model provides an embolic spring circle carries through the microcatheter, its characterized in that includes head structure and is the spring body that the spiral extends, the spring body with head structure links to each other, the spring body is used for releasing in the tumor intracavity, the head structure includes at least two butt pieces, at least two butt pieces with the spring body links to each other, works as the spring body is in one-level spiral state, just the butt piece is in when opening naturally, at least two butt pieces all with the axis of spring body is the contained angle, the contained angle is less than or equal to 90, just the contained angle is greater than 45, works as embolic spring circle release in the tumor intracavity, the butt piece is than the spring body contacts tumor chamber wall earlier, just the butt piece with the contact of tumor chamber wall is the face contact.

2. The embolic coil of claim 1, wherein when said spring body is in a primary helical state and said abutment plates are in a natural open position, said at least two abutment plates each form an angle with the axis of said spring body, said angle being less than or equal to 90 ° and said angle being greater than or equal to 60 °.

3. The embolic coil of claim 1, wherein the length of the abutment tab is 3 to 5 times the outer diameter of the spring body, and the maximum width of the abutment tab is 2 to 3 times the outer diameter of the spring body.

4. The embolic coil of claim 1, wherein each of said at least two abutment tabs comprises a plurality of wires, said plurality of wires being interlaced with one another to form a lattice structure.

5. The embolic coil of any of claims 1-4, wherein said abutment tab has an axial length L, said abutment tab includes a first end connected to said spring body and a second end opposite said first end, said abutment tab having a braid density K1 in a region extending L/3 from said first end in a longitudinal direction thereof toward said second end, said abutment tab having a braid density K2 in a region extending L/3 from said second end in a longitudinal direction thereof toward said first end, K1 > K2.

6. The embolic coil of claim 5, wherein the braid density of each of the at least two abutment plates decreases progressively from the first end to the second end.

7. The embolic coil of any of claims 1-4, wherein the abutment tab comprises a first end connected to the spring body and a second end opposite the first end, a section between the first end and the second end protruding to one side to form a first protruding section, a section between the first protruding section and the second end protruding to the other side to form a second protruding section, the protruding direction of the first protruding section being opposite to the protruding direction of the second protruding section, the first protruding being in abutment with the wall of the microcatheter when the embolic coil is loaded in a plurality of microcatheters for delivery, and both the second protruding and the second end being spaced from the wall of the microcatheter.

8. The embolic coil of claim 7, wherein the second end of the abutment tab is cocked relative to the second convex section in a direction in which the first convex section protrudes.

9. The embolic coil of claim 7, wherein said head structure further comprises an outer fixation ring and an inner fixation ring secured to each other, said outer fixation ring being sleeved outside said inner fixation ring, said wire heads of said abutment plates being gathered at a first end and secured between said outer fixation ring and said inner fixation ring, said outer fixation ring being fixedly inserted within said axial cavity of said spring body.

10. The embolic coil of any of claims 1-4, wherein each of said abutment tabs has a location of greatest width between its ends, the width of each of said abutment tabs decreasing from the greatest width to its ends, and wherein when said embolic coil is loaded into said microcatheter for delivery, the location of greatest width of adjacent two of said abutment tabs lies in different radial planes of said microcatheter.

11. Embolic coil according to any of claims 1 to 4, wherein at least two of said abutment plates are each covered with a coating.

12. A spring coil system comprising a microcatheter and an embolic spring coil of any of claims 1-11, loaded within and delivered through the microcatheter.