JP3434160B2 - Stent - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stent, and more particularly to an improvement of a stent used as one of treatment means for stenotic lesions of luminal organs.

[0002]

BACKGROUND OF THE INVENTION Recently, EMS (Expandable metallic) has been used as a permanent treatment for stenotic lesions such as carcinogenesis in luminal organs, which are also luminal organs of the digestive system.
Sent) has spread and good clinical results have been reported. The stent used here is a cylindrical net body made of metal or shape memory alloy or a cylindrical body made of plastic, and it is forcibly expanding the stenotic state by leaving it in the lesion. is there.

[0003]

However, the above-mentioned conventional stents may cause unexpected complications depending on the place of implantation, and as an example thereof, when the stent is placed in the lower esophageal stenosis or cardia cancer, gastric acid and stomach The contents often regurgitate, causing reflux esophagitis, nausea, and vomiting, which often makes treatment difficult.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention has been made by paying attention to the actual situation and problems of the above-mentioned conventional stents, and solves these problems and prevents reflux regardless of the place of indwelling, and reflux esophagitis. It is an object of the present invention to provide a stent having a novel structure capable of preventing the occurrence of complications such as the above.

[0005]

In order to achieve this object, the stent according to the present invention has elasticity, and a part of the main body of the stent having a substantially cylindrical shape has a backflow formed of a flexible material. The membrane that acts as a preventive valve is vertically installed, and the vertically extending portion of the membrane that is molded from this flexible material can be folded up to form a closed portion when a backflow is about to occur. Characteristically, the stent body is formed of a metal net body, the stent body is formed of a shape memory alloy, the stent body is formed of plastic,
The above-mentioned film body is made of a polytetrafluoroethylene-based ultra-thin film in which innumerable small holes are perforated for at least surface processing, and the above-mentioned film body is made of polyurethane. The body is made of latex, the erected portion of the film body is provided outside the lower end of the stent body, and the erected portion of the film body is made within the stent body. There is.

[0006]

[Advantages] With such a structure, the membrane body vertically laid on the stent body functions as a check valve due to its flexibility, and the vertically extending portion of the membrane body formed of a flexible material is prevented from flowing backward. When it is about to occur, it will be folded up to form an occlusion portion, which will block the passage of the reflux product, and prevent the occurrence of complications due to reflux.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a stent embodying the present invention, and FIG. 2 is a perspective view of an essential part showing a working state of a membrane body.

In these figures, reference numeral 1 indicates a main stent body. The main stent body is a net body made of metal (including shape memory alloy), which is also formed by forming a frog crochet net body into a substantially cylindrical shape.

Further, although this embodiment shows a stent body of a cylindrical body in which a frog is crocheted by a net body made of metal, the present invention is not limited to this material as shown in the claims. It can also be achieved by using other plastics, etc., and is not limited to the knitting method, etc., and at least it is intended to have a cylindrical shape when fully expanded.

Reference numeral 2 in the figure shows a film body, which is a polytetrafluoroethylene-based ultra-thin film having numerous small holes (trade name: GORE-TEX) formed on the surface of the material. It is a flexible material that is coated with or is molded by itself, and is rolled into a pipe shape.

Of course, in addition to the film material shown in this embodiment, other flexible materials such as polyurethane and latex can be used.

The membrane 2 is inserted into the stent body 1 described above, the lower end of which is vertically extended to form a vertically extending portion 2a, and the upper end is folded back to form the stent body 1. Is overlapped with the upper opening edge of the.

The attached state of the membrane body 2 is not only shown in the figure, but the length of the membrane body 2 is shortened so that the upper end is stopped in the middle of the main stent body 1 and the lower end of the main stent body 1 is attached. It is also possible to form the vertically extending portion 2a, or to fix the vertically extending portion 2a inside the stent body 1 by fixing the upper end of the membrane body 2 formed within the stent body 1 so as to be shorter than the stent body 1. .

The membrane 2 is integrated with the main stent body 1 and its folded portion, that is, the upper opening edge of the main stent body 1 and the lower end edge of the main stent body 1 by nylon threads 3a and 3b.

Further, this fastening structure also has a nylon thread 3a,
In addition to the adhesion by 3b or the like, it is possible to use a means such as the use of an adhesive or a fusion depending on the material.

Further, in the present embodiment, two Tegs 4 for insertion are inserted in the rolled film body 2 described above.
a and 4b are inserted therethrough, and the tips of the tegues 4a and 4b are entwined with each other at a position facing the lower end opening edge of the film body 2. Of course, other insertion means can be used instead of these Tegs 4a, 4b.

The stent according to this embodiment is configured as described above. The positional relationship between the stent body 1 and the membrane body 2 may be that the vertically extending portion 2a of the membrane body 2 is formed in a part of the stent body 1, and the membrane body 2 may be attached to the outside of the stent body 1, or It is possible to apply various modifications such as disposing the upper end of the film body 2 closer to the lower end of the stent body 1 or positioning it in the stent body 1, and the vertical portion 2a of the film body 2 flows backward. It only has to act as a preventive valve.

Here, the method of using this stent will be described assuming the case of lower esophageal cancer. Although the placement method differs depending on the configuration of the stent, in the embodiment shown in this figure, the tegu 4a, 4b are used. Utilizing this, the main stent body 1 is placed in front of the stenosis, and the membrane body 2 is placed from the anus side to the stomach. Next, the second stent is placed by inserting it into the already placed stent, but at this time, the upper end should be on the oral side of the first stent and the lower end should enter the stomach slightly from the connection between the esophagus and the stomach. Detain it in a standing place. As a result, the lesioned part is covered with the film body 2, and the suspended portion 2a of the film body 2 is left in the stomach.

Then, as shown in FIG. 2, when the regurgitation is about to occur, the vertically extending portion 2a placed in the stomach is folded up to form an occlusion portion, and the gastric contents This will prevent backflow. Further, depending on the structure of the stent, the indwelling position of the vertically extending portion 2a may be different, but the effect of preventing backflow by the vertically extending portion 2a is equal.

[0020]

The stent according to the present invention is constructed and used as described above. Therefore, in addition to preventing the backflow of gastric contents, which has been a problem in the past, it is possible to suppress tumor growth in the stent incidentally and eliminate dysphagia, thus improving the efficiency of therapeutic action. You can

[Brief description of drawings]

FIG. 1 is a perspective view of a stent embodying the present invention.

FIG. 2 is a perspective view of a main part showing a working state of a film body.

[Explanation of symbols]

1 Stent body 2 membrane 2a Vertical part 3a nylon thread 3b nylon thread 4a Tegus 4b Tegus

Claims (9)

(57) [Claims] 1. A flexible film-formed film body acting as a check valve is provided vertically on a part of a main stent body having elasticity and formed in a substantially cylindrical shape. A stent characterized in that the vertically extending portion of the membrane formed in (1) is folded up to form an occlusion when a backflow is about to occur. 2. The stent according to claim 1, wherein the main stent body is formed of a metal net body. 3. The stent according to claim 1, wherein the main stent body is made of a shape memory alloy. 4. The stent according to claim 1, wherein the main stent body is made of plastic. 5. The above-mentioned film body is made of a polytetrafluoroethylene-based ultra-thin film in which a large number of small holes are formed, and is used for at least surface treatment.
The stent according to claim 2, claim 3, or claim 4. 6. The stent according to claim 1, claim 2, claim 3, or claim 4, wherein the film body is made of polyurethane. 7. The stent according to claim 1, claim 2, claim 3, or claim 4, wherein the film body is made of latex. 8. The vertical portion of the membrane is formed outside the lower end of the main stent body.
The stent according to claim 2, claim 3, claim 4, claim 5, claim 6, or claim 7. 9. The hanging portion of the film body is formed in the main stent body, claim 1, claim 2, claim 3, claim 4, claim 5, claim 6, or claim 6. The stent according to claim 7.