Single-layer composite stent

Abstract

The invention discloses a single-layer composite stent, and relates to the field of medical instruments.The single-layer composite stent comprises a supporting body and a woven wire mesh, the supporting body is of a self-expanding mesh cylindrical structure, and a plurality of through holes are formed in the supporting body at intervals; the woven silk screen penetrates through the through hole and is wound on the supporting main body; the composite stent disclosed by the invention can treat stenosis lesion in a blood vessel through the supporting main body, effectively prevents plaques at the stenosis lesion from falling off through the weaving wires, realizes the effect of a double-layer stent by adopting the wall thickness of a single-layer stent, reduces the loss of a blood vessel cavity to the greatest extent, fully ensures smooth blood flow, and improves the treatment effect of the stenosis lesion. The obvious clinical significance is realized; the integral firmness and the composite strength of the single-layer composite stent are better, the risk of layering, even breakage and falling off is not easy to occur after the single-layer composite stent is implanted, and other complications are effectively prevented from being generated; meanwhile, the release resistance of the single-layer composite stent can be effectively reduced, and operation of a doctor is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a single-layer composite stent. Background Art

[0002] Causes such as atherosclerosis will cause stenosis in blood vessels, thus affecting the normal flow and supply of blood, leading to myocardial infarction, stroke, etc., and in severe cases, death. Among them, the most common site of vascular stenosis is the carotid artery. In order to improve carotid artery stenosis, metal stents are usually placed. The stents are usually implanted in the blood vessels in a compressed state. After reaching the stenotic site, the expanded state of the stent is used to open the blood vessel lumen.

[0003] In the process of using stents to treat carotid artery atherosclerosis, there are large gaps in the traditional stent structure. The expanded stent will cause the plaque to rupture and produce fragments. The released fragments will enter the bloodstream and flow to the small blood vessels in the brain, thereby causing a stroke.

[0004] Although traditional stents place embolic protection devices downstream during surgery, the carotid artery is a branching site, and plaques that fall off during stent expansion will escape from the gaps in the stent to the collateral vessels and cause blockage of the collateral vessels.

[0005] At present, in order to prevent small plaques from falling off, double-layer stents can be used. Double-layer stents are made by adding a layer of porous composite membrane to the basic support element of the bare stent. However, the double-layer stent is thicker, which will make patients feel uncomfortable after implantation; the outer layer is covered with dense porous membranes, which will cause greater friction with the delivery system during the stent release process, resulting in greater release resistance and affecting the doctor's operation. At the same time, double-layer stents usually use a composite of a porous polymer fiber layer and a metal stent, which makes it difficult to ensure the composite strength, resulting in the risk of delamination or even breakage and falling off after implantation, causing other complications. Summary of the invention

[0006] The main purpose of the present invention is to propose a single-layer composite stent, which aims to solve the technical problems of the current double-layer stent, such as large thickness affecting patient experience, large release resistance, difficulty in ensuring composite strength, and risk of delamination or even breakage and falling off after implantation.

[0007] In order to achieve the above-mentioned object, the present invention provides a single-layer composite stent, which comprises:

[0008] A support body, wherein the support body is a self-expanding net-shaped structure, and a plurality of through holes are arranged at intervals on the support body;

[0009] A woven wire mesh is passed through the through hole and is wound around the supporting body.

[0010] In some embodiments, the support body is a mesh cylindrical structure after expansion, and the woven wire mesh is penetrated into the through hole along the circumferential direction and / or axial direction of the support body and is wound around the support body.

[0011] In some embodiments, the support body includes a plurality of unit rings in a spiral structure, the plurality of unit rings are arranged at intervals along the axial direction of the support body, a plurality of connecting bridges are arranged between two adjacent unit rings, the plurality of connecting bridges are distributed at intervals along the circumference of the unit rings, and both ends of each connecting bridge are respectively connected to two connected unit rings;

[0012] The through holes are both provided on the unit ring and the connecting bridge.

[0013] In some embodiments, the unit ring includes a plurality of connected V-shaped units, the through holes are arranged on both sides of the V-shaped units, and the two ends of the connecting bridge are respectively connected to the ends of the V-shaped units in two adjacent connecting rings.

[0014] In some embodiments, in the circumferential direction of the unit ring, there are three V-shaped units between two adjacent connecting bridges.

[0015] In some embodiments, the woven wire mesh includes a plurality of annular wires, which are spaced apart along the axial direction of the support body, and the annular wires are passed through the through holes along the circumference of the unit rings and are respectively wound around the unit rings and the connecting bridges.

[0016] In some embodiments, the woven wire mesh includes a plurality of annular wires, which are spaced apart along the circumference of the support body, and the annular wires are passed through the through holes along the axial direction of the unit rings and are wound around the unit rings and the connecting bridges.

[0017] In some embodiments, the looped filament is in a helical loop structure.

[0018] In some embodiments, the diameter of the braided wires in the braided wire mesh is 1 / 10-1 / 3 of the thickness of the support body.

[0019] In some embodiments, the mesh size of the single-layer composite scaffold is in the range of 50-100 μm; and / or,

[0020] The outer diameter of the single-layer composite stent after self-expansion is in the range of 3-10 mm.

[0021] The single-layer composite stent provided by the present invention comprises a support body and a woven wire mesh, wherein the support body is a self-expanding mesh tube-shaped structure, and the support body is provided with a plurality of through holes at intervals; the woven wire mesh is inserted into the through holes and wound on the support body. The composite stent of the present invention can achieve the treatment of intravascular stenosis lesions through the support body, and effectively prevent the plaques at the stenotic lesions from falling off through the woven wire, and adopts the wall thickness of the single-layer stent to achieve the effect of the double-layer stent, minimize the loss of the vascular cavity, and fully ensure the smooth flow of blood, which has significant clinical significance. Since the woven wire mesh is inserted into the through holes and wound on the support body, the overall firmness and composite strength of the single-layer composite stent are better, and the risk of delamination or even breakage and falling off is not easy to occur after implantation, which effectively avoids the occurrence of other complications; at the same time, it can also effectively reduce the release resistance of the single-layer composite stent, which is convenient for doctors to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 A schematic structural diagram of an embodiment of a single-layer composite stent provided by the present invention;

[0024] Figure 2 for Figure 1 A schematic diagram of the structure of the middle support body;

[0025] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0026] Figure 4 for Figure 1 Schematic diagram of the structure of the woven wire mesh;

[0027] Figure 5 A schematic structural diagram of another embodiment of a single-layer composite stent provided by the present invention;

[0028] Figure 6 for Figure 5 Schematic diagram of the structure of the woven wire mesh.

[0029] Description of Figure Numbers:

[0030] 100-single-layer composite stent; 10-support body; 10a-through hole; 11-unit ring; 12-connecting bridge; 20-woven wire mesh; 21-annular wire.

[0031] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] In order to solve the technical problems that the current double-layer stent has a large thickness that affects the patient's feeling, causes a large release resistance, and is difficult to ensure the composite strength, and has the risk of delamination or even breakage and falling off after implantation, the present invention provides a single-layer composite stent 100.

[0037] Please refer to Figures 1 to 6In one embodiment of the present invention, a single-layer composite stent 100 includes a support body 10 and a woven wire mesh 20, wherein the support body 10 is a self-expanding mesh tube structure, and the support body 10 is provided with a plurality of through holes 10a at intervals; the woven wire mesh 20 is passed through the through holes 10a and is wrapped around the support body 10.

[0038] Specifically, the support body 10 is a mesh support structure formed by laser engraving of a superelastic memory metal tube and undergoing heat treatment or other processes, or a mesh support structure formed by 3D printing using superelastic memory metal powder, wherein the superelastic memory metal can be selected as nickel-titanium alloy, cobalt-chromium alloy or magnesium alloy. The support body 10 has an expansion state and a contraction state. When the single-layer composite stent 100 is transported, the support body 10 is in a contraction state. When the single-layer composite stent 100 is transported to the location of the intravascular stenosis, the single-layer composite stent 100 will release and present a radial expansion state, and after radial expansion, it will present a cylindrical structure, which can treat the intravascular stenosis. A plurality of through holes 10a are arranged at intervals along the circumference and axial direction of the support body 10. The shape of the through hole 10a can be selected as circular, square, elliptical or other reasonable shapes, and the size of the through hole 10a is larger than the radial size of the braided wire. The braided wire used in the braided wire mesh 20 is a nickel-titanium alloy wire, a cobalt-chromium alloy wire or a magnesium alloy wire. A plurality of braided wires are inserted into a plurality of through holes 10a and wound around the support body 10. The braided wire mesh 20 is formed after the plurality of braided wires are wound. During the winding process, the head end and the terminal end of the braided wire can be fixed on the support body 10 or in the through hole 10a by gluing or welding. The provision of the braided wire mesh 20 can reduce the mesh of the support body 10, so that the mesh formed by the single-layer composite stent 100 is relatively dense, which can effectively prevent the plaque from falling off at the stenotic lesion. Since the braided wire mesh 20 is wound around the through hole 10a of the support body 10, the wall thickness of the obtained single-layer composite stent 100 is the wall thickness of the support body 10, and the thickness has not increased. Moreover, the same metal material is used, so the delivery process and release process of the single-layer composite stent 100 are easier. Since the support body 10 is a self-expanding mesh tube structure, the woven wire mesh 20 wrapped around the support body 10 will not only expand radially with the support body 10, but also reduce the mesh area of ​​the support body 10. In this way, the single-layer composite stent 100 of the present invention can achieve plaque support while preventing fragments from falling off.

[0039] The single-layer composite stent 100 of the present invention can achieve the treatment of intravascular stenosis through the support body 10, and effectively prevent the plaque from falling off at the stenotic lesion through the braided wire, and adopt the wall thickness of the single-layer stent to achieve the effect of the double-layer stent, minimize the loss of the vascular cavity, fully ensure the smooth flow of blood, and have significant clinical significance. Since the braided wire mesh 20 is penetrated in the through hole 10a and wrapped around the support body 10, the overall firmness and composite strength of the single-layer composite stent 100 are good, and the risk of delamination or even breakage and falling off is not easy to occur after implantation, which effectively avoids the occurrence of other complications; at the same time, it can also effectively reduce the release resistance of the single-layer composite stent 100, which is convenient for doctors to operate.

[0040] In an optional embodiment of the present invention, the support body 10 is a mesh cylindrical structure after expansion, and the woven wire mesh 20 is penetrated into the through hole 10a along the circumferential direction and / or axial direction of the support body 10 and is wound around the support body 10 .

[0041] In this embodiment, the support body 10 has a mesh cylindrical structure after being expanded in its radial direction. The woven wire mesh 20 can be wound along the circumference of the support body 10 or along the radial direction of the support body 10. Of course, it can also be wound along both the circumference and the radial direction of the support body 10, or any other winding method, as long as it can reduce the mesh area of ​​the support body 10 and not increase the wall thickness.

[0042] See also Figure 2 and Figure 3 In one embodiment of the present invention, the support body 10 includes a plurality of unit rings 11 in a spiral structure, the plurality of unit rings 11 are arranged at intervals along the axial direction of the support body 10, a plurality of connecting bridges 12 are arranged between two adjacent unit rings 11, the plurality of connecting bridges 12 are distributed at intervals along the circumference of the unit rings 11, and both ends of each connecting bridge 12 are respectively connected to two connected unit rings 11, and the through holes 10a are provided on the unit rings 11 and the connecting bridges 12.

[0043] Specifically, the unit ring 11 is in a spiral ring structure, and after radial expansion, it is in a circular ring structure. Several unit rings 11 are arranged at equal intervals along the axial direction of the support body 10. Two adjacent unit rings 11 are connected by a connecting bridge 12. The connecting bridge 12 can be a straight line structure or a bent line structure. Two adjacent unit rings 11 are connected by a plurality of connecting bridges 12, and the plurality of connecting bridges 12 are distributed at equal intervals along the circumference of the unit ring 11. Each unit ring 11 is provided with a plurality of through holes 10a at intervals along its circumference. Optionally, the plurality of through holes 10a are located on the same cross section. Each connecting bridge 12 is provided with a through hole 10a. Optionally, the through hole 10a is provided in the middle position of the connecting bridge 12. With such a configuration, the plurality of through holes 10a on the support body 10 are distributed in an array along its circumference and axial direction, which is convenient for the winding operation of the woven wire mesh 20.

[0044] Furthermore, in an optional embodiment of the present invention, the unit ring 11 includes a plurality of connected V-shaped units, through holes 10a are arranged on both sides of the V-shaped units, and both ends of the connecting bridge 12 are respectively connected to the ends of the V-shaped units in two adjacent connecting rings.

[0045] Specifically, the through hole 10a is arranged in the middle of both sides of the V-shaped unit, and both ends of the connecting bridge 12 are respectively connected to the ends of the V-shaped unit. Such an arrangement can facilitate the processing and manufacturing of the support body 10.

[0046] In an optional embodiment of the present invention, the length of both side edges in the V-shaped unit is 2-3mm (for example, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm and the interval between any two endpoints), and when the single-layer composite stent 100 is in a compressed state, the angle between both side edges of the V-shaped unit is 1-3° (for example, 1°, 2°, 3° and the interval between any two endpoints), and after self-expansion, the angle between both side edges is 20-30° (for example, 20°, 22°, 25°, 28°, 30° and the interval between any two endpoints); the length of the connecting bridge 12 along the axial direction of the support body 10 is 1-2mm (for example, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm and the interval between any two endpoints).

[0047] In a specific embodiment of the present invention, in the circumferential direction of the unit ring 11, there are three V-shaped units between two adjacent connecting bridges 12. That is, one connecting bridge 12 is provided for every three V-shaped units.

[0048] Of course, in other embodiments of the present invention, there are two, four, or five V-shaped units between two adjacent connecting bridges 12, and the specific number is not limited and can be selected according to actual conditions.

[0049] See also Figure 1 and Figure 4In one embodiment of the present invention, the woven wire mesh 20 includes a plurality of annular wires 21, which are spaced apart along the axial direction of the support body 10, and the annular wires 21 are passed through the through hole 10a along the circumferential direction of the unit ring 11 and are respectively wound around the unit ring 11 and the connecting bridge 12.

[0050] In this embodiment, the woven wire mesh 20 is wound along the axial direction of the support body 10. Specifically, the annular wire 21 is a circular ring structure after radial expansion, and is evenly spaced through the through hole 10a along the axial direction of the support body 10 and is respectively wound around the unit ring 11 and the connecting bridge 12. Such a setting can effectively reduce the mesh area of ​​the support body 10, thereby effectively avoiding the falling off of the plaque, and also facilitates the winding operation of the annular wire 21.

[0051] The manufacturing steps of the single-layer composite stent 100 provided in this embodiment are as follows: (1) Use laser engraving or 3D printing to obtain a support body 10. The specific structure of the support body 10 refers to the above embodiment and will not be repeated here; (2) Take a nickel-titanium wire and wrap it around the through hole 10a of the V-shaped unit on the first unit ring 11 at one end of the support body 10, and fix the head end and the tail end of the nickel-titanium wire in the through hole 10a by gluing or welding; (3) Repeat the process of taking a nickel-titanium wire and wrapping it around the through hole 10a of the V-shaped unit on the first unit ring 11 at one end of the support body 10. (4) Repeat steps (2) and (3) to sequentially wind the second unit ring 11, the second connecting bridge 12, the third unit ring 11, the third connecting bridge 12 ... the nth connecting bridge 12, until all the unit rings 11 and the connecting bridges 12 on the supporting body 10 are wound, thereby completing the manufacture of the single-layer composite stent 100.

[0052] See also Figure 5 and Figure 6 In another embodiment of the present invention, the woven wire mesh 20 includes a plurality of annular wires 21, which are spaced apart along the circumference of the support body 10, and the annular wires 21 are passed through the through hole 10a along the axial direction of the unit ring 11 and are wound around the unit ring 11 and the connecting bridge 12.

[0053] In this embodiment, the braided wire mesh 20 is wound along the axial direction of the support body 10. Specifically, each annular wire 21 is inserted into the through hole 10a along the axial direction of the unit ring 11 and wound around the unit ring 11 and the connecting bridge 12, and a plurality of annular wires 21 are evenly spaced along the axial direction of the support body 10. Such a setting can effectively reduce the mesh area of ​​the support body 10, thereby effectively preventing the plaque from falling off, and also facilitates the winding operation of the annular wire 21.

[0054] It should be noted that the through holes 10a of the V-shaped units on two adjacent unit rings 11 wound with the same annular wire 21 may be arranged relative to each other or may be arranged in a staggered manner, which is not limited here.

[0055] In an optional embodiment of the present invention, the annular wire 21 is in a spiral annular structure, that is, the through holes 10a of the V-shaped units on two adjacent unit rings 11 wound by the same annular wire 21 are staggered, so that the annular wire 21 is in a spiral annular structure after winding and self-expanding.

[0056] The manufacturing steps of the single-layer composite stent 100 provided in this embodiment are as follows: (1) using laser engraving or 3D printing to obtain a support body 10. The specific structure of the support body 10 refers to the above embodiment and will not be described in detail here; (2) taking a nickel-titanium wire, starting to wind the wire along the through hole 10a of one of the V-shaped units on the first unit ring 11 at one end of the support body 10, and sequentially passing through the through hole 10a of one of the V-shaped units on the second unit ring 11, the through hole 10a of one of the V-shaped units on the third unit ring 11, and so on. a, until reaching the through hole 10a on the last unit ring 11 at the other end of the support body 10, return to the through hole 10a on the first unit ring 11, and fix the head and tail ends of the nickel-titanium wire in the through hole 10a by gluing or welding; (3) repeat taking a nickel-titanium wire, opening a through hole 10a that is one V-shaped unit different from step (2) to open the wire winding, and perform the wire winding in the manner of step (2); until all the unit rings 11 and the connecting bridges 12 on the support body 10 are wound, thus completing the manufacture of the single-layer composite stent 100.

[0057] In an optional embodiment of the present invention, the diameter of the braided wire in the braided wire mesh 20 is 1 / 10-1 / 3 of the thickness of the support body 10 (for example, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, 1 / 3 and the interval between any two end points). With such a design, the single-layer composite stent 100 not only has the thickness of the support body 10, but also can reduce the mesh size of the support body 10 through the braided wire mesh 20, thereby achieving coverage of the plaque and preventing the falling of fragments.

[0058] In an optional embodiment of the present invention, the diameter of the braided wire in the braided mesh 20 is 20-50μm (for example, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm and an interval value between any two end points). With such a design, the size of the through hole 10a and the wall thickness of the supporting body 10 do not need to be designed to be larger, thereby ensuring that the overall weight of the single-layer composite bracket 100 is lighter and the operation is more convenient.

[0059] In an optional embodiment of the present invention, the mesh aperture of the single-layer composite stent 100 ranges from 50 to 100 μm (such as 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm and any interval between the two end points). Such a design can achieve coverage of plaques and effectively prevent the shedding of fragments.

[0060] In an optional embodiment of the present invention, the outer diameter range of the single-layer composite stent 100 after self-expansion is 3-10mm (for example, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm and the interval between any two end points) to adapt to blood vessel cavities with different inner diameters in different parts for the treatment of carotid artery atherosclerosis.

[0061] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A single-layer composite stent, characterized in that: The single-layer composite stent comprises: A support body, wherein the support body is a self-expanding net-shaped structure, and a plurality of through holes are arranged at intervals on the support body; A woven wire mesh is passed through the through hole and is wound around the supporting body.

2. The single-layer composite stent according to claim 1, characterized in that: The support body is a mesh cylindrical structure after expansion, and the woven wire mesh is penetrated into the through hole along the circumferential direction and / or axial direction of the support body and is wound around the support body.

3. The single-layer composite stent according to claim 2, characterized in that: The support body comprises a plurality of unit rings in a spiral structure, the plurality of unit rings are arranged at intervals along the axial direction of the support body, a plurality of connecting bridges are arranged between two adjacent unit rings, the plurality of connecting bridges are distributed at intervals along the circumference of the unit rings, and both ends of each connecting bridge are respectively connected to two connected unit rings; The through holes are both provided on the unit ring and the connecting bridge.

4. The single-layer composite stent according to claim 3, characterized in that: The unit ring includes a plurality of connected V-shaped units, the through holes are arranged on both sides of the V-shaped units, and the two ends of the connecting bridge are respectively connected to the ends of the V-shaped units in two adjacent connecting rings.

5. The single-layer composite stent according to claim 4, characterized in that: In the circumferential direction of the unit ring, three V-shaped units are arranged between two adjacent connecting bridges.

6. The single-layer composite stent according to claim 3, characterized in that: The braided wire mesh includes a plurality of annular wires, which are spaced apart along the axial direction of the support body, and the annular wires are passed through the through holes along the circumference of the unit rings and are respectively wound around the unit rings and the connecting bridges.

7. The single-layer composite stent according to claim 3, characterized in that: The braided wire mesh includes a plurality of annular wires, which are spaced apart along the circumference of the support body, and the annular wires are passed through the through holes along the axial direction of the unit rings and are wound around the unit rings and the connecting bridges.

8. The single-layer composite stent according to claim 7, characterized in that: The annular filament is in a spiral annular structure.

9. The single-layer composite stent according to any one of claims 1 to 8, characterized in that: The diameter of the braided wires in the braided wire mesh is 1 / 10-1 / 3 of the thickness of the support body.

10. The single-layer composite stent according to any one of claims 1 to 8, characterized in that: The mesh pore size of the single-layer composite stent is in the range of 50-100 μm; and / or, The outer diameter of the single-layer composite stent after self-expansion is in the range of 3-10 mm.

Images