JP3009638U - Stent - Google Patents

Abstract

(57) [Summary] [Objective] A stent composed of an elastic body, the shape of which has the most desirable non-cylindrical cross-sectional shape of a biological conduit, and a stent whose surface is partially or entirely coated with a biocompatible material. The purpose is to provide. [Structure] A continuous body or group of spring wires bent into an open leg shape and their vertices and ends are bound together,
In a stent constructed as a node with an assembly of two threads bound in an annular shape, the stent has a non-uniform cylindrical cross-section capable of changing the length of the binding thread and inflating it into the most desirable shape for a biological duct. To provide a stent. Also,
The outer surface, inner surface, side surface, etc. of all or part of the surface of a cylindrical stent having a stretchable and elastic elasticity and having a uniform cross section is coated with a biocompatible resin to form all or part of the wall into a film shape. Provided is a stent characterized by being reinforced with a mesh when covered.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention can be placed in a constriction, a constriction site, an arteriovenous aneurysm site, etc. of a living body, for example, a blood vessel, an esophagus, a trachea, a urethra, a bile duct, an intestinal tract, to expand the duct, Alternatively, the present invention relates to a treatment device for a biological duct, such as securing a duct similar to an artificial blood vessel.

[0002]

[Prior art]

 As a means for expanding the constriction site such as the biliary tract, arteriovenous blood vessels, esophagus, trachea, etc., it is self-expanding by heating after insertion, which is made in a contracted shape using shape memory alloy, resin, etc. Methods, such as a type in which a pressed net-like metal thin plate stent is inserted by a balloon catheter and expanded by the inflation force of a balloon, or a material using a sprinkling wire have been developed.

[0003]

[Problems to be solved by the device]

 However, these conventional stents have irreversible expansion and contraction, the degree of expansion cannot be adjusted, and because of the uniform cross-sectional shape of the cylinder, there is a high possibility of expanding to a site that does not need to be expanded. In addition, in order to improve stretchability and expansion performance, the surface of the stent material is reticulated or porous, and in the case of malignant tumor etc., after implantation, the ganglion cells erode into the stent and re-occlude. There is a large possibility that it cannot be used for isolated decompression treatment of aneurysms in cases such as arteriovenous aneurysms. Further, there is a drawback that foreign matter is likely to adhere to the inner surface of the stent, especially in the trachea.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problem, one of the present inventions is to provide an open leg shape of a spring, for example, a continuous body or group of spring wires bent in V shape or U shape, and their apexes and ends. A non-uniform cylinder capable of expanding into a most desirable shape for a living body conduit in a stent constructed as one node of an assembly of two threads bound and annularly bound to each other. Provided is a stent having a cross section. Another aspect of the present invention is characterized in that all or part of the surface such as the outer surface, the inner surface, and the side surface is coated with a resin having a high biocompatibility, and all or part of the wall is formed into a film shape. Providing stains. Another aspect of the present invention is to cover all or part of the outer surface, inner surface, side surface, etc. of a stent having a uniform cross-section cylindrical shape with expandable elasticity with a biocompatible resin. Provided is a stent characterized in that all or a part of the wall is made into a film shape. The last one of the present invention is characterized in that a biocompatible mesh is reinforced on the outside or inside of the tube at the coating site in order to increase the film strength of the coating when coating the above biocompatible resin. To provide a stent.

[0005]

[Action]

 Since the stent according to the present invention 1 is formed into a desired shape of the living body duct before insertion, it expands without giving an excessive expansion force to the tissue when it is inserted into the living body duct and expanded. . In addition, the stent according to the second, third, and fourth embodiments of the present invention prevents re-erosion of cancer cells into the duct because the wall has no opening. Also, in the case of arteriovenous varices, the aneurysm is blocked from the duct. Also, the adhesion of foreign matter to the inner surface of stainless steel is reduced.

[0006]

【Example】

 The present invention is illustrated by the following non-limiting examples. FIG. 1 illustrates one of the basic configurations of claim 1 of the present invention. The twisted coil spring 10 has each open leg portion incorporated in the connecting pipe material 11. One open leg portion of the torsion coil spring 10 arranged on the opposite side is also incorporated in the connecting pipe material 11, and is fixed by brazing, caulking or the like. Two binding yarns 12 bind at the vertices of the continuum of these spring wires and are linked in an annular shape. This one knot carries the force of radial spreading and the length of the tying thread determines the maximum diameter when inflated. For example, since the binding thread 13 is longer than the binding thread 12, the stent diameter is also large. FIG. 3 shows an example in which a stent having the same node is assumed to have another biological conduit shape, for example, a trumpet shape. It is obtained by gradually shortening the length of the binding yarns 15, 16, 17, 1819, 20 in the figure. FIG. 4 and FIG. 5 show a drum type and a drum type, respectively, by changing the lengths of the binding yarns 22, 23, 24 and the binding yarns 31, 32, 33 of a stent having a known knot mechanism. Here is an example. FIG. 6 shows an embodiment relating to claim 2 of the present invention. This figure shows an example in which only the trumpet portion is covered. The present invention does not need to cover the entire surface, but depends on the required surgical procedure and case. The biocompatible membrane 42 is formed of a very thin membrane. The coating method of the biocompatible material may be either dipping or thin film adhesion. In the case of depping, the lump of binding yarn is also wrapped, which makes it difficult to damage the living vascular tissue. FIG. 2 illustrates the case where the stent of FIG. 1 in which the stent of FIG. 1 is coated with a biocompatible film is inserted into the blood vessel 14 and left indwelling. FIG. 7 illustrates claim 3 of the present invention, and FIG. 8 illustrates claim 4 of the present invention. In FIG. 8, the mesh 63 is made of biocompatible resin or stainless steel mesh that does not impair the elasticity of the stent.

[Advantages of the Invention] Since the stent according to the first invention is formed into the desired shape of the living body duct before insertion, it can be expanded without giving an excessive expansion force to the tissue when expanded. In addition, the stent according to the present invention 2, 3 and 4 has an effect of preventing re-erosion of cancer cells into the duct because the wall does not have an opening portion, and in the case of arteriovenous aneurysm, isolation decompression of the aneurysm portion. Allows treatment. It also has the effect of reducing the adhesion of foreign matter to the inner surface of the stent.

[Brief description of drawings]

1 is a perspective view of an embodiment of the present invention 1;

FIG. 2 is a cross-sectional view of an example in which the stent of FIG. 1 is inserted into a living body tube.

FIG. 3 is a perspective view of a trumpet-type stent of the first invention.

FIG. 4 is a perspective view of a drum type stent of the present invention 1.

FIG. 5 is a perspective view of the hourglass-shaped stent of the present invention 1.

FIG. 6 is a perspective view of an embodiment of the present invention 2;

FIG. 7 is a perspective view of an embodiment of the present invention 3;

FIG. 8 is a perspective view of an embodiment of the present invention 4;

[Explanation of symbols]

10 ... torsion coil spring 11 ... connecting pipes 12, 13, 14, 15, 16, 17, 18, 19, 2
0 ... Bundling yarn 21 ... Spring wire 22, 23, 24 ...
・ Bundling thread 30 ・ ・ ・ Spring wires 31, 32, 33 ・ ・
-Bundling thread 40 ... Spring wire 41 ... Bundling thread 42 ... Biocompatible film 50 ... Spring wire 51 ... Bundling thread 52 ... Biocompatible film 60 ... Spring wire 61 ... Bundling yarn 62 ... Biocompatible membrane 63 ... Mesh

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[Procedure amendment]

[Submission date] October 25, 1994

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

Claims (4)

[Scope of utility model registration request] 1. An open leg shape of spring, for example a continuum or group of spring wires bent into a V or U shape,
Constrain their vertices and ends into an annular shape 2
A stent constructed by assembling a bundle with a thread of a book as one node, characterized in that the length of the binding thread is changed and has a non-uniform cylindrical cross-section capable of expanding into a shape most desirable for a living vessel. . 2. The whole or a part of the surface such as the outer surface, the inner surface, the side surface or the like is coated with a resin having high biocompatibility, and the whole or a part of the wall is formed into a film shape. The stent according to. 3. A stent having a uniform cross-section and having a cylindrical shape having expandable and contractible spring properties, wherein all or part of the surface such as the outer surface, the inner surface, and the side surface is coated with a resin having high biocompatibility, and all or one of the walls. A stent having a film-shaped portion. 4. The biocompatible mesh is reinforced on the outside or inside of the tube at the site to be covered in order to increase the film strength of the covering.
The stent according to.