WO2018049868A1

WO2018049868A1 - Tectorial stent

Info

Publication number: WO2018049868A1
Application number: PCT/CN2017/090596
Authority: WO
Inventors: 刘香东
Original assignee: 先健科技(深圳)有限公司
Priority date: 2016-09-13
Filing date: 2017-06-28
Publication date: 2018-03-22
Also published as: CN107811726A; CN107811726B

Abstract

Disclosed is a tectorial stent, comprising a metal stent (10) and tectorial membranes (20, 30) covering a surface of the metal stent (10), wherein a bonding layer (40) is provided between the tectorial membranes (20, 30) and the surface of the metal stent (10). The tectorial membranes (20, 30) are closely combined with the metal stent (10) via the bonding layer (40), wherein same can prevent the membranes from falling off.

Description

Covered stent

[Technical Field]

The invention relates to the field of interventional medical device technology, in particular to a stent graft.

【Background technique】

With the continuous development of interventional medical devices and interventional procedures, transcatheter intervention, implantation of various prosthetic valves, artificial blood vessel stents have become an important method for the treatment of valvular disease, hemangioma and vascular stenosis.

Both the prosthetic valve and the artificial blood vessel stent include a stent graft, and the stent graft generally includes a metal stent and inner and outer layers covering the inner and outer surfaces of the metal stent, respectively. Wherein the metal stent is prepared by using a superelastic metal for self-expanding into a shape compatible with a valve or a blood vessel in the body, and supporting a coating covering the inner and outer surfaces of the metal stent; the inner and outer The film is used to block blood flow from the surface of the stent graft.

In the preparation of the above-mentioned stent graft, the metal stent is fixedly disposed between the inner layer coating and the outer layer coating by heat-compression bonding the inner layer coating film and the outer layer coating film.

The stent graft prepared by the above method, especially after the artificial valve containing the stent graft is implanted into the body, the inner and outer membranes and the metal stent are easy to be washed under the blood flow with the passage of time. Peeling occurs, causing the metal stent to be unable to support the inner and outer layers of the film, so that the stent graft cannot block blood flow.

[Summary of the Invention]

Based on this, it is necessary to provide a stent-graft that is tightly bonded to the metal stent to reduce the possibility of peeling off the metal stent and the coating.

The present invention provides a stent graft comprising a metal stent and a coating covering the surface of the metal stent, and a bonding layer disposed between the coating and the surface of the metal stent.

The metal stent may be covered with an outer layer coating only on its outer surface or only with an inner layer coating on its inner surface; it may also be covered with a coating on both its outer and inner surfaces. The covering may be to completely cover the entire surface or to cover a portion of the surface.

When the metal stent is covered with a film only on one surface thereof, the bonding layer is disposed between the film and the surface on which it is placed. When both surfaces of the metal stent are covered with a film, the bonding layer may be disposed between any coating film and a surface thereof, and correspondingly, the film not coated with the bonding layer may be directly covered. The bonding layer is provided on the surface on which it is located; or between each film and the surface on which it is placed.

In one embodiment, the material of the bonding layer is polytetrafluoroethylene or parylene.

In one embodiment, the bonding layer has a thickness of from 0.1 um to 50 um.

In one embodiment, the stent graft further includes a transition layer disposed between the metal stent and the bonding layer.

In one embodiment, the material of the transition layer is silicon dioxide or epoxy.

In one embodiment, the metal bracket has a hollow tubular shape, and a plurality of hollows are formed on a side of the metal bracket.

In one embodiment, the stent graft is a body frame or a vascular stent of a prosthetic valve.

The film of the stent graft of the present invention is connected to the metal stent through the adhesive layer. Since the adhesive layer and the metal stent have good bonding force, the adhesive layer and the film also have good bonding force, and therefore, the film passes through The bonding layer can be tightly bonded to the metal stent, which reduces the possibility of peeling off the metal stent and the coating.

[Description of the Drawings]

Figure 1 is a schematic view showing the structure of a stent graft of the present invention.

2 is a schematic cross-sectional view of the stent graft of FIG. 1 in a radial direction.

3 is a schematic structural view of a metal stent of the stent graft of FIG. 1.

4 is an enlarged schematic view showing the structure of the stent graft of FIG. 2 at A.

FIG. 5 is an enlarged schematic view showing another structure of the stent graft of FIG. 2 at A. FIG.

Fig. 6 is a schematic view showing the structure of another stent graft according to the present invention.

Fig. 7 is an enlarged schematic view showing a partial structure of the stent graft of Fig. 6.

Figure 8 is a schematic illustration of a stent graft applied to a heart valve.

【detailed description】

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to FIG. 1 and FIG. 2, the stent graft 100 of the present invention is a hollow tubular structure including a metal stent 10, an inner layer coating 20 covering the inner surface of the metal stent 10, and an outer layer covering the outer surface of the metal stent 10. Membrane 30. Wherein, the metal stent 10 is a support body of the stent graft 100 for expanding the stent graft 100 and adhering to the wall of the human body cavity; the inner layer coating film 20 and the outer layer coating film 30 are used for coating the membrane The stent 100 forms a laterally sealed lumen such that blood flow only flows through the lumen of the stent graft 100 and does not ooze out from the side of the stent graft 100.

The stent graft 100 in this embodiment is a main body frame of a prosthetic valve. After at least two closable leaflets 60 are disposed in the lumen of the stent graft 100, a prosthetic valve as shown in FIG. 8 is formed. The artificial valve is radially compressed and implanted into the damaged valve of the human body via a catheter to replace the damaged valve to realize the physiological function of the damaged valve. It can be understood that the stent graft 100 can also be a partial structure of other medical instruments or medical instruments implanted in the human body. For example, the stent graft 100 can also be a blood vessel stent for treating hemangiomas.

Referring to FIG. 3, the metal bracket 10 has a hollow tubular shape, and the metal bracket 10 has an integral structure. The "integral structure" in the present invention means that the metal bracket 10 is formed by laser cutting and heat setting of a metal tube, or the metal bracket 10 is composed of a plurality of components fixedly connected, for example, the metal bracket 10 is formed by welding two components. A plurality of hollows 101 are formed on the side of the metal bracket 10 so that the sides of the metal bracket 10 are hollowed out.

The metal bracket 10 is made of a superelastic or shape memory function metal material such as Nitinol, Nitinol, Nitinol or an alloy thereof. In the present invention, the metal stent 10 is cut by a nickel-titanium tube, and the outer diameter of the nickel-titanium tube is preferably 5 mm to 12 mm, and the wall thickness of the nickel-titanium tube is preferably 0.2 mm to 0.6 mm. First, the plurality of hollows are cut by laser on the nickel-titanium tube; then, the cut nickel-titanium tube is expanded under heat treatment conditions to a diameter suitable for a humanized damaged valve to obtain a metal stent 10, In the invention, the nickel-titanium tube is preferably expanded to 25 mm to 35 mm. It can be understood that the metal bracket 10 can also be woven with nickel titanium wire.

It can be understood that the metal bracket 10 can also be composed of a plurality of separate components. At this time, the metal bracket 10 is no longer a unitary structure. For example, the metal bracket 10 can be composed of a plurality of separated metal rings, and the plurality of separated metal rings are The axes are coincidently welded such that the plurality of separate metal rings are combined to form a hollow tubular metal bracket 10, in which case each of the metal rings may include the hollow, or each two adjacent metal rings The interfitting forms the hollow.

Referring to FIG. 4 in conjunction with FIG. 2, in the present invention, the stent graft 100 further includes an adhesive layer 40 coated on the inner and outer surfaces of the metal stent 10. The bonding layer 40 can be prepared by various methods, such as coating or spraying a polymer adhesive on the inner and outer surfaces of the metal stent 10, or sputtering the particles on the inner and outer surfaces of the metal stent 10, or by vapor deposition. It is deposited on the inner and outer surfaces of the metal bracket 10. The bonding force between the bonding layer 40 and the surface of the metal stent 10, the bonding layer 40 and the inner layer coating 20 or the outer layer coating 30 may be a mechanical bonding force or a chemical reaction between the two. The resulting chemical bonding force, for example, when the bonding layer 40 is an epoxy resin or an acrylic resin binder, the inner and outer surfaces of the epoxy resin or acrylic resin and the metal stent 40, and the inner layer coating 20 and the outer film 30 also have chemical bonding. In the present invention, the material of the bonding layer 40 is preferably polytetrafluoroethylene or parylene.

The inner layer coating 20 covers the inner surface of the metal bracket 10 including the bonding layer 40, and the outer layer coating 30 covers the outer surface of the metal bracket 10 including the bonding layer 40, and is subjected to hot pressing composite treatment. The layer film 20 and the outer layer film 30 are directly joined at the hollow 101, and the inner layer film 20 and the outer layer film 30 are connected to the metal holder 10 through the adhesive layer 40, respectively.

The material of the inner layer coating film 20 and the outer layer coating film 30 may each be a thermoplastic polymer material. In the present invention, the materials of the inner layer coating film 20 and the outer layer coating film 30 are preferably ePTFE (expanded polytetrafluoroethylene). And the inner layer film 20 and the outer layer film 30 are each formed by superposing a plurality of layers of ePTFE single layer film. In the stent graft 100 of the present invention, the inner and outer membranes 20 and 30 are connected to the metal stent 10 through the adhesive layer 40. Since the adhesive layer 40 and the metal stent 10 have good bonding force, the adhesive layer 40 The inner and outer covering films 20 and 30 also have a good bonding force. Therefore, the inner and outer covering films 20 and 30 are tightly bonded to the metal bracket 10 through the bonding layer 40, thereby reducing the metal bracket 10 and the inner portion. The outer coverings 20, 30 may cause peeling, especially for the prosthetic valve, during the opening and closing of the leaflets, the inner covering 20 can resist the impact of blood flow, and can avoid falling off the surface of the metal stent 10; Since the bonding layer 40 is coated on the inner and outer surfaces of the metal bracket 10, the possibility of metal ions released by the metal bracket 10 is reduced, and the possibility of surface oxide particles falling off of the metal bracket 10 is also reduced, and the stent graft is ensured. 100 safety after implantation in the body.

In the present invention, the thickness of the bonding layer 40 is preferably 0.1 um to 50 um, and the bonding layer 40 has good bonding force with the metal stent 10 and the inner and outer covering films 20 and 30 within the thickness range, and There is also no effect on the radial compression size of the stent graft 100. When the thickness of the adhesive layer 40 is less than 0.1 um, the surface of the adhesive layer 40 is liable to cause defective defects such as pinholes, thereby causing the bonding force of the adhesive layer 40 and the metal stent 10 or the adhesive layer 40 and the inner and outer layers. The bonding force of the films 20, 30 is small. When the stent graft 100 is implanted in the body, the inner and outer covering films 20, 30 may still peel off from the metal stent 10; when the thickness of the bonding layer 40 is greater than 50 um, The radial compression size of the stent graft 100 is significantly increased, so that the stent graft 100 cannot be loaded into the delivery catheter with a smaller inner diameter after being radially compressed, so that it cannot be implanted into the body through a catheter having a smaller inner diameter, and when the adhesive layer is When the thickness of 40 is greater than 50 um, the ability of the bonding layer 40 to conform to the deformation of the metal stent 10 is weakened, and therefore, when the metal stent 10 is deformed, the bonding layer 40 is easily peeled off from the metal stent 10.

It can be understood that the adhesive layer 40 may not completely cover the entire inner and outer surfaces of the metal bracket 10, that is, the adhesive layer 40 may be selectively covered on a part of the surface of the metal bracket 10 as needed, and the partial surface may be the metal bracket 10 The entire inner surface, or may be the entire outer surface of the metal bracket 10, or may also be part of the inner surface and/or a portion of the outer surface of the metal bracket 10. For example, in another embodiment, the bonding layer 40 may cover only the inner surface of the metal bracket 10, the inner layer coating 20 is tightly bonded to the metal bracket 10 through the bonding layer 40, and the outer layer coating 30 directly covers the metal. The outer surface of the stent 10 is heat-pressed with the inner layer coating 20 at the hollow portion 101. When the stent graft 100 is implanted into the lumen of the body, the outer membrane 30 is tightly pressed against the lumen wall due to the expansion of the metal stent 10. Therefore, even if the outer layer coating 30 is not tightly bonded to the metal holder 10 through the bonding layer 40, the possibility of peeling between the metal holder 10 and the outer layer coating 30 is small.

Referring to FIG. 5 , in another embodiment of the present invention, the stent graft 100 may further include a transition layer 50 . The transition layer 50 is disposed between the metal bracket 10 and the bonding layer 40 for further improving the connection of the bonding layer 40 to the metal bracket 10. The transition layer 50 adopts a material having a bidirectional bonding ability with the metal bracket 10 and the bonding layer 40, that is, the transition layer 50 has a strong bonding force with the metal bracket 10, and the transition layer 50 and the bonding layer 40 also have a strong bond. Binding force. In the present invention, the material of the transition layer 50 is preferably silicon dioxide or epoxy resin. In the present invention, the thickness of the transition layer 50 is preferably from 1 μm to 50 μm.

Referring to FIG. 6 and FIG. 7, a stent graft 100a according to another embodiment of the present invention has substantially the same structure as the stent graft 100 except that the stent graft 100a includes only the metal disposed through the adhesive layer 40a. The inner layer coating 20a on the inner surface of the stent 10a does not include an outer layer coating. When the stent graft 100a is implanted into the human lumen, the inner membrane 20a of the stent graft 100a prevents blood flow from oozing out from the side of the stent graft 100a, and the outer surface of the metal stent 10a directly contacts the lumen wall of the human body. The friction between the stent graft 100a and the wall of the human body lumen is improved, and the stent graft 100a is prevented from moving relative to the human lumen under the impact of blood flow.

It can be understood that in other embodiments, the film combined with the metal support through the adhesive layer may also be only the outer film. In this case, the adhesive layer may cover the entire inner surface and a part of the outer surface of the metal support. , or the adhesive layer can also cover the entire inner surface of the metal stent and the entire outer surface, so that not only can the metal stent be more effectively prevented from releasing metal ions, thereby causing allergies, and the surface oxide particles of the metal stent can be more effectively prevented. Peel into the blood and form a blood clot.

The technical features of the above-described embodiments may be arbitrarily combined. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be considered as the scope of this manual.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A stent graft comprising a metal stent and a coating covering the surface of the metal stent, wherein an adhesive layer is disposed between the coating and the surface of the metal stent.
The stent graft according to claim 1, wherein the stent graft comprises an inner layer coating covering the inner surface of the metal stent and an outer layer coating directly covering the outer surface of the metal stent. The bonding layer is disposed between the inner layer film and the inner surface of the metal bracket.
The stent graft according to claim 1, wherein the stent graft comprises an inner layer coating directly covering an inner surface of the metal stent and an outer layer coating covering an outer surface of the metal stent. The bonding layer is disposed between at least a portion of the outer surface and the outer layer coating.
The stent graft according to claim 1, wherein the stent graft comprises an inner layer coating covering an inner surface of the metal stent and an outer layer film covering an outer surface of the metal stent, An adhesive layer is disposed between the inner film and the inner surface, and between the outer film and the outer surface.
The stent graft according to claim 1, wherein only the outer surface of the stent graft is covered with an outer layer coating, and an adhesive layer is disposed between the outer layer coating and the outer surface, or The inner surface of the stent graft is covered with an inner layer coating, and the adhesive layer is disposed between the inner layer coating and the inner surface.
The stent graft according to any one of claims 1 to 5, wherein the material of the adhesive layer is polytetrafluoroethylene or parylene.
The stent graft according to any one of claims 1 to 5, wherein the adhesive layer has a thickness of 0.1 um to 50 um.
The stent graft according to any one of claims 1 to 5, wherein the stent graft further comprises a transition layer disposed between the metal stent and the adhesive layer.
The stent graft according to claim 8, wherein the material of the transition layer is silica or epoxy.
The stent graft according to any one of claims 1 to 5, wherein the stent graft is a main body frame or a blood vessel stent of a prosthetic valve.