JPH0539706Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a medical balloon for use in dilating and paturing constricted parts of biological lumens such as the esophagus, blood vessels, and bile ducts, and for removing foreign bodies such as blood clots. It concerns catheters.

[Conventional technology]

Generally, when dilating a narrowed part of a biological lumen, a balloon is used instead of an elastic material such as rubber to prevent pressure from being applied locally due to deformation of the balloon and to prevent the balloon from expanding beyond a certain limit. itself expands
Pre-molded balloons made of non-shrinkable resin are used and are highly valued. However, these molded resin balloons usually achieve their purpose by inflating them with liquid and maintaining a certain shape, but when they deflate, the balloon remains bulky around the catheter body, so it may cause damage to the body. It is difficult to smoothly insert and remove the balloon into a lumen, and there is also a risk that the bulky balloon portion may damage the inner wall of a small blood vessel. The most common method for manufacturing molded balloons is to stretch them to increase their strength.
When using a balloon with a larger diameter than the diameter of the catheter on which it is attached, the wall thickness becomes too thin and the pressure resistance is unavoidable, and there is a natural limit to the balloon diameter due to the required pressure resistance. . It is possible to add reinforcing material to increase the strength of these molded balloons, but they cannot be expanded and deflated freely, are bulkier than the resin molded balloons mentioned above, and wrinkle when deflated. The problem is that the remaining part tends to get in the way of insertion, removal, etc., and that it is difficult to obtain a sufficient expansion diameter. Furthermore, what these balloons have in common is that the balloon itself does not have the function of deflating, so normally the fluid injected for inflation is removed by suction to deflate the balloon, but the response is slow and There are drawbacks such as the need for force to suction and remove fluids, etc.

On the other hand, a balloon has been proposed in which the strength of the balloon is increased by combining an elastic material such as rubber with cloth or a braided material, and the balloon is prevented from expanding beyond a certain limit.

For example, in Japanese Patent Publication No. 57-23506, stenosis is achieved using a balloon catheter in which a three-layer cloth bag is interposed between a double rubber tube and a spherical or square tube, and a rubber band is adhered to the surface of the cloth bag. A cleaving device is disclosed. Although this device has certain functions and features, it is difficult and complicated to manufacture, such as simply overlapping the rubber tube and cloth bag, gluing the rubber band, and adjusting the whole thing, or the finish of the balloon part. It is not necessarily satisfactory in terms of size and bulk. Furthermore, manufacturing such a balloon catheter with good reproducibility requires skill and there are restrictions on controlling the way the balloon inflates, so it is not practical except for testing and research purposes. It is hard to say that it is a method.

Furthermore, in Japanese Patent Application Laid-open No. 59-91970, a tube made of a braided material is used, and an inelastic coating of a semi-hard material is applied to the outside of the portion that will become the shaft of the catheter. A dilatation catheter is disclosed that has an elastic coating on the inside and on both the inside and outside of the portion that becomes the balloon. However, this catheter is reinforced with braided material over almost its entire length, and the covering material is different between the outside and inside, or between the shaft and balloon parts, or the braided material is only used in the part that will become the balloon. The problem is that the manufacturing process becomes extremely complicated.

Furthermore, in order to overcome these drawbacks, the present inventors invented a balloon catheter consisting of a composite structure in which a stretchable knitted fabric and an elastic material were combined and integrated, and the invention was published in Japanese Patent Application Laid-Open No. 63-29660. and disclosed in JP-A-63-77461. This creates shaped balloons with different external shapes and diameters by partially adjusting the coarseness of the braid, combining the types and thicknesses of the threads, and partially adjusting the wall thickness of the elastic material. However, there is a limit to the range that can be adjusted, and the manufacturing process becomes complicated, resulting in high costs.

[The problem that the idea attempts to solve]

It is made of a composite material that combines a braided material and an elastic material, and when expanded, the outer diameter changes at specific points.
A catheter having a balloon that can be inflated at different times by setting an inflation order,
In addition to simplifying the balloon manufacturing process,
The purpose of the present invention is to provide a medical balloon catheter that enables reduction in manufacturing costs.

[Means to solve the problem]

That is, the present invention combines an elastic material with a stretchable cylindrical knitted knitted fabric in which the balloon serves as a reinforcing material in a balloon catheter that dilates and opens a constricted area in a biological lumen by inflating a balloon. This is a medical balloon catheter characterized by comprising an integrated composite structure part and an overlapping structure part in which a knitted fabric is interposed between two thin film-like elastic materials.

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 according to an embodiment of the present invention. As shown in FIG. 1, the balloon 1 includes a layered structure 5 in which a knitted material 4 is interposed between an inner elastic material 2 and an outer elastic material 3, and a layered structure 5 in which a knitted material 4 is interposed between the elastic materials 2, 3 and the knitted material 4. It consists of an integrated structure part 6 that is integrated with the main body tube 7 of the catheter. In manufacturing, for example, first, a cylindrical knitted fabric material 4 is placed over a cylindrical elastic material 2 attached to an inner metal core. At this time, a release agent is applied to the area that will become the overlapping structure 5, or a thin film-like material having hydrophobicity and solvent resistance is wrapped around and interposed therebetween. Then, cover it with the above-mentioned film material to protect it. Next, the integrated structure part 6
The elastic material 2 and the knitted fabric material 4 are integrated at the portion where they become. The method is not particularly stipulated, but the elastic material 2 may be bonded with a solvent or elastic flexible adhesive, or it may be immersed in a solution of the elastic material while attached to the core bar and dried to integrate. You can also use this method.

The elastic material 3 is placed over these, and the integrated structure 6 is bonded and integrated using a solvent for the elastic material 2 or a stretchable and flexible adhesive. Finally, the film-like material is removed and attached and fixed to the main body tube 7 of the catheter.

In the balloon 1 produced in this manner, the overlapping structure 5 is simply overlapped as compared to the integrated structure 6. Therefore, when the balloon 1 is inflated, the elastic materials 2, 3 and the knitted material 4 slide against each other as the balloon inflates. This means that the inherent elastic expansion of the elastic materials 2, 3 is not hindered as much. Also, the inherent spread of the stitches of the knitted material 4 and the stretch of the fibers themselves are not hindered as much, so that the inflation ratio of the balloon is naturally greater. This is a fundamental difference in nature.

Therefore, as shown in FIG.
expands first, then the integrated structure 6 expands,
Furthermore, as shown in FIG. 2b, the final expanded shape is such that the overlapping structure portion 5 has a larger expanded outer diameter than the integrated structure portion 6, and as shown in FIG. , patency, and pressure hemostasis can be performed, so there is no risk of damage caused by forcefully expanding a narrow area to fit a wide area, and there is also no risk of damage caused by applying force to a narrow area. Treatment can be performed without putting extra pressure on the area. Further, even if the entire length of the narrowed portion 8 is the same, there is no problem in use, and conversely, the portion that expands first may be hooked onto the tip of the narrowed portion and used for positioning.

In the catheter of the present invention, it is desirable that the outer diameter of the balloon 1 when deflated is made smaller to be equal to the outer diameter of the main body tube 7. To this end, the wall thickness of the balloon 1 should be as thin as possible, depending on the type and purpose of the elastic material used, but it should be in the range of 0.2 to 1 m/m considering pressure resistance during inflation, etc. is appropriate. Although the compressive strength varies depending on the application, it is preferably 2 to 8 kg/cm ² or more.

The knitted fabric material 4 used in the present invention is a cylindrical knitted fabric, and the material is not particularly limited.
From a functional standpoint, it is preferable to use fibers that have a certain degree of elasticity, and suitable materials include spandex (polyurethane fiber), where the fiber itself is a rubber elastic material, and woolly nylon that has been treated with elasticity.
Polyester fibers, polyamide fibers, etc. can also be used for applications that do not require large elongation. Further, for the purpose of achieving a balance between the required strength and the degree of elongation, it is preferable to use a yarn that is a composite of fibers of other materials, since the strength and elongation can be easily adjusted. As for the knitting method for knitting materials, it is best to use one with a large degree of expansion and contraction of the stitches, and weft (horizontal) stockinette knitting, which stretches and contracts mainly in the circumferential direction, is suitable. It is preferable to use knitting, stockinette knitting, rubber knitting, etc.

The elastic bodies 2 and 3 may be made of rubber materials suitable for expansion and contraction, such as latex rubber, silicone rubber, and thermoflexible elastomer, and are used in combination with the knitted fabric material 4.

The expansion ratio of the balloon is adjusted to about 1.5 to 5 times, but the expansion ratio, strength, and ease of stretching of the balloon can be adjusted by adjusting the type of yarn, knitting method, and stitch density of the knitting material. This can be achieved by appropriately selecting and combining the types of elastic materials. In addition, the overlapping structure portion 5 of these balloons
Although a plurality of combinations of the integrated structure portion 6 and the integrated structure portion 6 can be considered, generally, for example, overlapping portion:integrating portion = 1:1, or overlapping portion:integrating portion:overlapping portion = 1:1:
A combination of 1 is appropriate.

[Effect of idea]

The medical balloon catheter according to the present invention is capable of shaping and inflating a single balloon with different inflation diameters depending on the position. In addition to being able to perform therapeutic treatments effectively and safely, it is also possible to easily produce products with consistent quality such as expansion behavior and extruded shape, making them extremely useful medically. Provides equipment.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the structure of a balloon according to an embodiment of the present invention. Figure 2 is a diagram showing the inflated state of the balloon according to the present invention, (a) shows the state at the start of inflation, (b) shows the final state of inflation, and (c) shows the degree of stenosis differing depending on the position. A situation in which a stenosis is dilated is shown.

Claims (1)

[Scope of utility model registration request] In a balloon catheter that dilates and opens a constricted area in a biological lumen by inflating a balloon, the balloon combines and integrates an elastic material with a stretchable cylindrical knitted knitted fabric serving as a reinforcing material. A medical balloon catheter characterized in that it is comprised of a composite structure part and a superimposed structure part in which a knitted fabric is interposed between two thin film-like elastic materials.