CN114504411B

CN114504411B - A bracket

Info

Publication number: CN114504411B
Application number: CN202011186431.3A
Authority: CN
Inventors: 王禹都; 王大伟; 张一�; 叶萍; 杨鹏飞
Original assignee: Shanghai Achieva Medical Suzhou Co ltd
Current assignee: Shanghai Achieva Medical Suzhou Co ltd
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2024-12-31
Anticipated expiration: 2040-10-29
Also published as: CN114504411A

Abstract

The present application discloses a stent, wherein the stent is a self-expandable tubular grid structure, the two ends of the tubular grid structure are open, and the stent includes a plurality of connected first grid units, the first grid unit includes a plurality of side bars, and the cross-sectional area of the side bars gradually increases in the direction from the middle of the side bars to the two ends of the side bars. By setting the side bars of the first grid unit to gradually increase in the cross-sectional area of the side bars in the direction from the middle to the two ends, the stiffness of the side bars gradually increases in the direction from the middle to the two ends, reducing the strain amount of the end of the side bar and the area near the end, so that the stress and strain distribution of the stent is uniform when deformed, avoiding the concentration of stress and strain in the local area, and avoiding the deformation of the stent that affects the size, thereby improving the resilience of the stent.

Description

Support frame

Technical Field

The application belongs to the technical field of medical appliances, and particularly relates to a bracket.

Background

Interventional procedures, such as delivery of stents using microcatheters, dilation balloons, embolic coils, etc., to a designated lesion site have become standard procedures for treating vascular disorders. The use of this method is very effective in treating diseases in locations where some traditional surgical methods are at great risk.

In recent 30 years, interventional therapy mainly based on stent implantation has rapidly progressed, and has become an important means for cardiovascular and cerebrovascular diseases. Stent implantation is based on percutaneous transluminal angioplasty, whereby a stent is delivered to a lesion through a catheter and expanded, supporting and dredging the vessel. Stents are now commonly used to treat vascular stenosis and aneurysms, with continued development. When used for treating stenosis, the plaster has the functions of supporting a stenosed vessel, keeping the vessel unobstructed and reducing the occurrence rate of restenosis. For the treatment of aneurysms, the function is to assist in supporting embolic coils, and/or to provide a blood flow guiding effect, with the ultimate goal of providing a gradual healing of the reduced blood flow within the aneurysm. However, the existing bracket is uneven in stress and strain distribution, and the problem that the size is affected by deformation, the rebound resilience is reduced and the like can be caused by long-term bearing of larger stress and strain, so that the product performance is seriously affected.

Disclosure of Invention

The application provides a bracket, which aims to solve the technical problems that the deformation of the existing bracket is caused by long-term bearing of larger stress strain, and the size and rebound resilience of the existing bracket are influenced.

In order to solve the technical problems, the technical scheme is that the support is of a self-expandable tubular grid structure, two ends of the tubular grid structure are open, the support comprises a plurality of connected first grid units, each first grid unit comprises a plurality of side bars, and the cross-sectional area of each side bar is gradually increased in the direction from the middle of each side bar to two ends of each side bar.

According to one embodiment of the application, the width of the side bar is gradually increased in a direction along the middle of the side bar to the two ends of the side bar.

According to an embodiment of the present application, the first grid unit includes two first side bars disposed opposite to each other and two second side bars disposed opposite to each other, the first side bars of the first grid units are connected to form a plurality of first lines spiraling along a first direction, the second side bars of the first grid units are connected to form a plurality of second lines spiraling along a second direction, the first direction is staggered with the second direction, and the length of the first side bars is greater than the length of the second side bars.

According to one embodiment of the present application, the maximum width of the two ends of the first side bar is smaller than the maximum width of the two ends of the second side bar.

According to an embodiment of the present application, a ratio of a maximum width of two ends of the second side bar to a minimum width of a middle of the second side bar is greater than or equal to 1.1 and less than or equal to 1.75.

According to an embodiment of the present application, a ratio of the maximum width of the two ends of the first side bar to the minimum width of the middle of the first side bar is greater than or equal to 1.05 and less than or equal to 1.5.

According to one embodiment of the application, the first side bar and the second side bar are wavy.

According to one embodiment of the present application, the second side bars of the plurality of first grid cells are connected to form four second lines of spirals along the second direction, and the second lines of the four spirals are circumferentially arranged at intervals of 90 °.

According to an embodiment of the application, developing structures are arranged on the first grid cells at both ends of the tubular grid structure.

According to one embodiment of the application, the bracket is formed by cutting and shaping a shape memory alloy pipe.

The application has the beneficial effects that the sectional area of the side rods is gradually increased in the direction from the middle part to the two ends by arranging the side rods of the first grid units, so that the rigidity of the side rods is gradually increased in the direction from the middle part to the two ends, the strain quantity of the end parts of the side rods and the areas close to the end parts is reduced, the stress and the strain distribution of the bracket are uniform during deformation, the stress and the strain concentration of the local areas are avoided, the deformation of the bracket is avoided, the size is influenced, and the rebound resilience of the bracket is improved.

Drawings

For a clearer description of the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:

FIG. 1 is a schematic view of the overall structure of an embodiment of the bracket of the present application;

FIG. 2 is a schematic view of the overall deployment of an embodiment of the stent of the present application;

FIG. 3 is a schematic view of a partially expanded configuration of an embodiment of a stent of the present application;

FIG. 4 is a schematic view of a stent of the present application in a bent configuration to show the change in distance between nodes on the inner and outer sides;

FIG. 5 is a schematic view of an embodiment of the stent of the present application for showing a second line shape in which two lines spiral in a second direction;

FIG. 6 is a schematic view showing a structure of an embodiment of the stent of the present application when bent, for showing a second wire shape in which two wires are spiraled in a second direction;

fig. 7 is a schematic diagram of a side bar width structure of a first grid cell of an embodiment of a bracket of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Referring to fig. 1 to 3, fig. 1 is a schematic overall structure of an embodiment of the stent of the present application, fig. 2 is a schematic overall unfolded structure of an embodiment of the stent of the present application, and fig. 3 is a schematic partially unfolded structure of an embodiment of the stent of the present application.

An embodiment of the present application provides a stent 100, as shown in fig. 1 and 2, the stent 100 is a self-expandable tubular mesh structure, two ends of the tubular mesh structure are open, and the stent 100 includes a plurality of connected first mesh units 10. The first grid cell 10 includes a plurality of side bars 11, and the cross-sectional area of the side bars 11 is gradually increased in a direction along the middle of the side bars 11 to both ends of the side bars 11.

Because the stent 100 needs to be stored in the introducer sheath before use, long-term exposure to large stress strain can cause problems such as reduced deformation, size and rebound resilience, which seriously affect product performance, and the stress strain of the side bars 11 of the grid cell is more concentrated at both ends. In the application, the sectional area of the side rod 11 of the first grid unit 10 is gradually increased along the direction from the middle to the two ends, so that the rigidity of the side rod 11 is gradually increased along the direction from the middle to the two ends, the strain quantity of the end part of the side rod 11 and the area close to the end part is reduced, the stress and the strain distribution of the bracket 100 are uniform during deformation, the stress and the strain concentration of the local area are avoided, the deformation of the bracket 100 is avoided, the size is influenced, and the rebound resilience of the bracket 100 is improved.

In addition, the stent 100 of the present application is a closed loop stent having suitable radial force and recyclability. Suitable radial forces may cause the stent to retract elastically against the vessel, support embolic coils within the aneurysm, and create sufficient friction with the vessel to avoid stent displacement. The recyclability may be recovered or repositioned after the stent releases the microcatheter, allowing for increased surgical tolerance and for the stent 100 to be adjusted to the desired placement.

In one embodiment, the width of the side bar 11 is gradually increased in a direction from the middle of the side bar 11 to both ends of the side bar 11, so that the rigidity of the side bar 11 is gradually increased in a direction from the middle to both ends, reducing the amount of strain at the ends of the side bar 11 and near the end regions, and making the stress and strain distribution of the bracket 100 uniform at the time of deformation. By arranging the side bars 11 with different widths at different positions and redistributing the stress-strain distribution, adverse effects caused by stress-strain concentration in local areas can be effectively reduced, other performances of the bracket 100 are not affected, and the rebound resilience of the bracket 100 is improved. The width change of the side rod 11 can be formed by cutting, which is beneficial to processing.

In other embodiments, the thickness of the side rail 11 increases gradually in a direction from the middle of the side rail 11 to both ends of the side rail 11, so that the rigidity of the side rail 11 increases gradually in a direction from the middle to both ends, reducing the amount of strain at the ends of the side rail 11 and near the end regions, and making the stress and strain distribution of the bracket 100 uniform when deformed. By arranging the side bars 11 with different thicknesses at different positions, the stress and strain distribution can be redistributed, so that adverse effects caused by stress and strain concentration in local areas can be effectively reduced, other performances of the bracket 100 are not affected, and the rebound resilience of the bracket 100 is improved. Of course, in other embodiments, the width and thickness of the side bar 11 may be gradually increased along the direction from the middle of the side bar 11 to the two ends of the side bar 11, so as to gradually increase the cross-sectional area of the side bar 11, and further gradually increase the rigidity of the side bar 11 along the direction from the middle to the two ends, so that the stress and strain distribution of the bracket 100 during deformation are uniform, and local stress and strain concentration is avoided.

The existing bracket 100 system is designed in a closed-loop structure because of the required recoverability, and the bracket units in the closed-loop structure have the defects of poor bending flexibility and easier folding. As shown in fig. 2 and 3, the first grid cell 10 includes two oppositely disposed first side bars 111 and two oppositely disposed second side bars 112, and the first grid cell 10 resembles a quadrilateral. The plurality of first grid cells 10 are connected by nodes, and the first side bars 111 of the plurality of first grid cells 10 are connected to form a plurality of first line patterns spiraling in a first direction, the second side bars 112 of the plurality of first grid cells 10 are connected to form a plurality of second line patterns spiraling in a second direction, the first direction and the second direction are staggered, and the length of the first side bars 111 is greater than the length of the second side bars 112.

Since the first side bars 111 of the plurality of first grid cells 10 are connected, it can be regarded as a plurality of first line patterns spiraling in the first direction, and the second side bars 112 of the plurality of first grid cells 10 are connected, it can be regarded as a plurality of second line patterns spiraling in the second direction. The first line type formed by the first side bar 111 and the second line type formed by the second side bar 112 may be regarded as beams, respectively. And the second side bar 112 is shorter, has higher rigidity and is easier to maintain its own shape, so that when the stent 100 is bent, the second wire shape formed by the second side bar 112 plays a dominant role in the shape of the stent 100, so that it basically maintains a spiral shape, similar to the braiding effect. While the first side bar 111 is longer and acts like a flexible connection, the stent 100 can be deformed accordingly as it passes through a curved vessel having a varying length of the inner and outer side paths. Fig. 4 is a schematic view showing the structure of an embodiment of the stent of the present application when it is bent, for illustrating the distance change between the nodes on the inner and outer sides, as shown in fig. 4. The marking curve connects node distances from the inner side to different positions of the outer side, when the marking curve is bent, the distance between the connecting nodes of the two first grid cells 10 on the inner side can be greatly reduced, the distance between the connecting nodes of the two first grid cells 10 on the outer side can be greatly increased, and the marking curve can adapt to the change of the path length of the inner side and the outer side. Through the structural design, the main body shape of the bracket 100 can be kept, the flexibility can be improved, the bending performance of the bracket 100 is effectively improved, and the length change of the inner side and the outer side of bending is adapted. Because of the good flexibility of the stent 100, the stent can adequately conform to the inner wall of a vessel at the bend, avoiding stenotic thrombosis and restenosis within the stent.

Specifically, as shown in fig. 5 and 6, fig. 5 is a schematic structural view of an embodiment of the stent of the present application for showing a second wire form in which two wires are spiraled in a second direction, and fig. 6 is a schematic structural view of an embodiment of the stent of the present application for showing a second wire form in which two wires are spiraled in a second direction when bent. The second side bars 112 of the plurality of first grid cells 10 are connected to form four second wire patterns spiraling in the second direction, that is, the main body structure of the stent 100 forms four second wire patterns spiraling, and the four second wire patterns are circumferentially arranged at intervals of 90 °. As shown in fig. 5 and 6, when the stent 100 is bent, two of the second wires shown in the drawings are respectively positioned at the inner side and the outer side, so that the variation of the path length at the inner and outer sides does not greatly restrict the structure.

Further, as shown in fig. 3, the first side bar 111 and the second side bar 112 have a wave shape, and the wave shape of the first side bar 111 and the second side bar 112 further improves the resilience and the flexibility of the bracket 100 compared to a straight line shape. In addition, in a specific embodiment, the second side rod 112 has an S shape, the first side rod 111 is connected in two S shapes, and when the inner and outer path lengths of the first side rod 111 change, the first side rod is more easily deformed correspondingly.

As shown in fig. 3, since the first side bar 111 and the second side bar 112 have different lengths, the stress and strain distribution of the bracket 100 is not uniform when being deformed, and a large stress-strain concentration is generated. The second side bar 112 has a shorter length, which plays a role in maintaining the basic shape of the bracket 100, so that the average width of the second side bar 112 needs to be larger than that of the first side bar 111, the rigidity of the second side bar is improved, the second side bar has better supporting force, the stress and the strain distribution are uniform during deformation, and the stress and the strain concentration in a local area are avoided. Specifically, as shown in fig. 7, fig. 7 is a schematic view of a side bar width structure of a first grid cell according to an embodiment of the bracket of the present application. The maximum width W ₂ at the two ends of the first side rod 111 is smaller than the maximum width W ₁ at the two ends of the second side rod 112, so that the rigidity of the two ends of the second side rod 112 is improved, the stress and strain concentration of the second side rod 112 with higher stress at the two ends is avoided, the stress and strain distribution is effectively uniform, and the overall rebound resilience of the bracket 100 is improved.

Specifically, the minimum width W ₀ of the middle portion of the first side lever 111 and the minimum width W ₀ of the middle portion of the second side lever 112 may be the same. The minimum width W ₀ in the middle of the first side rod 111 gradually increases to transition to the maximum width W ₂ at both ends, and the ratio of the maximum width W ₂ at both ends of the first side rod 111 to the minimum width W ₀ in the middle of the first side rod 111 is 1.05 or more and 1.5 or less, for example, 1.05, 1.25, 1.5, etc., and the width of the first side rod 111 in the ratio range is designed reasonably, so that stress and strain distribution can be effectively uniform. The ratio of the maximum width W ₁ at both ends of the second side bar 112 to the minimum width W ₀ at the middle of the second side bar 112 is 1.1 or more and 1.75 or less, for example, 1.1, 1.3, 1.5, 1.75, etc. The width of the second side rail 112 in this ratio range is reasonably designed to effectively even out stress and strain distribution. By increasing the width where the first side bar 111 and the second side bar 112 of the first grid cell 10 are more stressed, and in turn increasing their stiffness, the amount of strain is reduced, effectively even stress and strain distribution, and the resilience of the bracket 100 as a whole is improved.

In one embodiment, the developing structure 120 is provided on the first grid cell 10 at both ends of the tubular grid structure. Specifically, the developing structure 120 is located on the first side lever 111 or the second side lever 112. Of course, the developing structure 120 may also be disposed at a connection node of the first side lever 111 and the second side lever 112. Developing structure 120 is fabricated from materials that develop well under X-rays, including but not limited to platinum, tantalum, gold, and alloys thereof.

In one embodiment, the stent 100 is formed from a shape memory alloy tubing by cutting and shaping. The metal stent 100 made of the shape memory alloy tube has sufficient radial supporting force to ensure good adhesion. The shape memory alloy has super-elastic property, so that the stent 100 can be greatly deformed after being subjected to external circumferential constraint force, and the stent 100 can still completely recover the shape after the constraint force is removed. This capability may compress the outer diameter of stent 100 so that it can fit into a microcatheter with delivery device function. Specifically, the stent 100 is a metal stent manufactured by carving a shape memory alloy tube having a superelastic effect by laser and performing post-setting treatment. Preferably, the alloy material can be nickel-titanium alloy with super-elastic property.

In summary, the stent 100 of the present application can have suitable radial force, good flexibility and recyclability.

The foregoing description is only illustrative of the present application and is not intended to limit the scope of the application, and all equivalent structures or equivalent processes or direct or indirect application in other related technical fields are included in the scope of the present application.

Claims

1. A stent, characterized in that the stent is a self-expandable tubular grid structure, the two ends of the tubular grid structure are open, and the stent comprises a plurality of connected first grid units, the first grid units comprise a plurality of side bars, and the cross-sectional area and width of the side bars gradually increase in the direction from the middle of the side bars to the two ends of the side bars;

The first grid unit includes two first side bars arranged opposite to each other and two second side bars arranged opposite to each other, the length of the first side bar is greater than the length of the second side bar, and the widths at both ends of the first side bar are smaller than the widths at both ends of the second side bar;

The first side bars of the first grid units are connected to form a plurality of first lines spiraling along a first direction, and the second side bars of the first grid units are connected to form a plurality of second lines spiraling along a second direction, wherein the first direction is staggered with the second direction.

2 . The bracket according to claim 1 , wherein a ratio of a width at both ends of the second side bar to a width in a middle portion of the second side bar is greater than or equal to 1.1 and less than or equal to 1.75.

3 . The bracket according to claim 1 , wherein a ratio of a width at both ends of the first side bar to a width in a middle portion of the first side bar is greater than or equal to 1.05 and less than or equal to 1.5.

The bracket according to claim 1 , wherein the first side bar and the second side bar are wavy in shape.

5. The bracket according to claim 1, characterized in that the second side bars of a plurality of the first grid units are connected to form four spiral second line shapes along the second direction, and the four spiral second line shapes are arranged at 90° intervals in the circumferential direction.

6 . The stent according to claim 1 , wherein a developing structure is provided on the first grid units located at both ends of the tubular grid structure.

7. The stent according to claim 1, characterized in that the stent is formed by cutting and shaping a shape memory alloy tube.