JPS6377461A - Medical balloon catheter - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a medical balloon used to remove foreign bodies such as blood clots and stones formed in living body lumens such as blood vessels, bile ducts, and urethra. It concerns catheters.

[Prior art]

An example of a case where the balloon catheter of the present invention is used is a balloon catheter for removing a thrombus.The catheter is delivered through a blood vessel to the site where a thrombus exists, the balloon is inflated, and the catheter is inserted in that state. There is a therapy in which the balloon is pulled out and the blood clot is scraped out and removed. This method has become widely used in recent years because it is less invasive than major surgeries such as open heart surgery, is inexpensive, and allows for relatively easy removal of thrombi.

Catheters currently on the market for this purpose are made to be stretchable so that they can easily pass through blood vessels or thrombus sites, and latex rubber balloons are used. There are many examples. However, in the case of such a balloon catheter, the shape of the inflated balloon is an arc, and the blood clot removal performance is poor.
In addition, there is a risk that the blood clot that has fallen off may escape from the arcuate portion of the balloon when scraped out with the balloon, resulting in the formation of a new blood clot.

On the other hand, in order to remove blood clots efficiently and reliably, balloon-shaped balloons with a concave or umbrella-like shape on the withdrawal side have been proposed. As the balloon is a molded resin balloon shaped like an umbrella, it is inevitable that there will be rot on the outer periphery even when it is not inflated.
Therefore, when inserting the balloon into a blood vessel, there is a problem that the operation becomes complicated, requiring a separate tool, such as inserting the balloon portion while being wrapped in a sheath. Furthermore, when scraping out blood clots with a balloon, the balloon has little elasticity and maintains a fixed shape, so although it is effective in removing blood clots, a large force is applied to the inner wall of the blood vessel when passing through the blood vessel. There is a risk of damage.

[Purpose of the invention]

The present invention overcomes these problems of conventional balloon catheters for removing foreign bodies such as blood clots and stones, and
The object of the present invention is to provide a medical balloon catheter that has excellent insertability and foreign body removal performance and can be used safely.

[Structure of the invention]

That is, the present invention provides that a balloon is formed from a composite material that integrates a braided material whose mesh structure changes depending on the region and an elastic material, and that the balloon maintains a specific shape when inflated. Characteristic medical balloon catheter.

Hereinafter, the medical balloon catheter of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the structure of a balloon catheter according to an embodiment of the present invention in a state in which the balloon portion (1) is deflated. The balloon part (1) is made of a composite material that integrates a cylindrical silk material (4) and an elastic material (5), and is fixed to the tape body (3) near the catheter tip (2). .

The braided material (4) is a cylindrical knitted fabric and is not particularly limited in terms of material, but from a functional standpoint it is preferably a fiber that has a certain degree of elasticity, such as snogu latex (polyurethane fiber), woolly, etc. Nylon etc. are suitable. In addition, in order to balance the required strength and degree of elongation, it is possible to use yarns made of fibers of other materials.
This is suitable because the strength and elongation can be easily adjusted. The method of knitting the braided material is preferably one that allows the stitches to have a large degree of expansion and contraction, and methods such as stockinette knitting and rubber knitting are suitable.

The elastic material (5) may be made of rubber materials suitable for expansion and contraction, such as latex rubber, silicone rubber, or thermoplastic nystomer, and is used in combination with the braided material (6). As a method for compositing, an appropriate method suitable for the purpose may be used, such as a dipping method, a coating method, a lamination method, or a superimposition method.

Further, the mesh structure of the braided material (4) is locally changed to correspond to the desired shape when the balloon is inflated, and the degree of expansion and contraction is varied.

FIG. 2 shows the balloon portion (
1) is a schematic diagram showing the expanded state.

FIG. 2(a) shows an example in which the rear end (7) of the balloon is formed in a flat shape, and the front end (8) is tapered and rounded. These can be obtained by changing the mesh structure of the rear end (7) to be coarser than that of the front part (8). In addition, FIG. 2(b) shows that the central part (1
In the example where 1) is formed in a concave shape, the mesh structure in the center part (11) should be made tighter at both ends to make it difficult to stretch.
You can get good results.

As mentioned above, as a method for partially adjusting the stitch structure, that is, the degree of expansion and contraction of the braided material (4), specifically, (1) changing the stitch density of the braided material (4); For example, the mesh density of the front and rear large diameter parts (9) and (10) in FIG. 2(b) is set to 40 to 65 wells and 50 to 75 courses.
In this case, by increasing the number of wells and the number of courses in the central part (11) by 20 to 30, it is possible to create a constriction in the central part (11) when the balloon is inflated.

■Increase the thickness of the thread in some areas to make it difficult to stretch.

For example, in the example of FIG. 2(b), the overall number is 50 to 20.
A thread of 0 denier is used, and a thread 0 to 100 denier thicker than the whole is used for the central part (11) where the constriction is to be provided. In addition, in the example of FIG. 2(a), the rear end (7)
A method of increasing the thickness of the thread in several stages from the front part (8) to the front part (8) is also suitable.

■Increase the number of threads in some areas to increase the density. For example, in the example shown in Figure 2), one thread of 50 to 200 denier is used overall, and one thread of 60 to 100 denier is used for the constriction in the center (11). ,2
Main knitting.

■Partially change the type of thread or add a different type of thread. For example, in the example shown in Fig. 2(b), a thread of Snow Z-index with an overall elongation of 100 to SOO% or one woolly nylon thread with an elongation of 20 to 50 yen is used, and the central part is The part (11) where the constriction is provided has low elasticity, so one thread with low elongation is added and knitted with two threads, or it is used alone.

■Changing the knitting method locally to create a stitch structure that makes it difficult for the stitches to stretch. For example, in the example shown in Fig. 2(b), the overall material is stockinette knitting or rubber knitting, which has a high degree of expansion and contraction, and the part where the constriction of the central part (11) is to be made is made of tuck knitting, which is difficult to stretch, or floating knitting. Change to stop.

By combining one or more of these methods, a braided material with desired stretch characteristics can be obtained.

It is also an effective means to adjust the thickness distribution of the entire balloon as necessary, or to make the shape of the braided material into a predetermined shape so that it will be easier to achieve the desired shape during inflation. be.

These balloons are made of a composite material that integrates a braided material and an elastic material and maintain appropriate rigidity, so they can be inflated to the appropriate size and inserted into the catheter without stretching the balloon to its inflation limit. Even if it is moved within a blood vessel, etc.
Because it maintains the desired shape and has appropriate elasticity, it can fully achieve its purpose, and the procedure can be performed safely and effectively without overdoing it and damaging the blood vessel wall. can.

〔Effect of the invention〕

The balloon catheter according to the present invention can be easily and safely inserted into a living body lumen such as the above-mentioned incision, blood vessel, biliary tract, or urethra. When it is pulled out, it reliably scrapes and removes foreign matter and does not damage the inner walls of blood vessels, etc., so the treatment is highly effective), making it extremely useful in the medical industry.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a state in which the balloon portion of a balloon catheter according to an embodiment of the present invention is deflated. Furthermore, FIG. 2 is a schematic view showing the state in which the balloon portion of the balloon catheter of the present invention is inflated. (a) is an example in which the front portion of the balloon is rounded in a chi-shape, and (b) is an example in which a concave constriction is provided in the center of the balloon.

Claims (1)

[Claims] (1) Forming a balloon with a composite material that integrates a braided material with a different mesh structure depending on the part and an elastic material,
A medical balloon catheter characterized in that the balloon maintains a specific shape when inflated.