JPH02142576A - Catheter - Google Patents

Abstract

PURPOSE:To enable the stable and precise practice of insertion regulating operation without injuring the inner wall by forming the top end part made in porous texture and softened by fibrillation by drawing integrally with a close tube by polytetrafluoroethylene. CONSTITUTION:A porous texture part 2 by a resin is formed in the top end part of a polytetrafluoroethylene tube 1 having a close texture, and a connector 3 is mounted to the base end side of the tube 1. The formation of the top end part 2 made in porous texture by fibrillation by drawing on one end of the close tube 1 of polytetrafluoroethylene prevents the injuring of the inner walls of the blood vessels and heart by the top end part. As the intermediate part and the other end side are made of the close tube of polytetrafluoroethylene, such catheter has preferable torque property, the advancing or rotating operation by an external operator is made easy and precise, and a precise and safe handling operation is realized. The close tube part and the porous and soft top end part are integrally bonded to achieve the firm and stable connection between the close tube part and the top end part.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECT OF THE INVENTION The present invention relates to the invention of a catheter that does not damage the inner walls of blood vessels or internal organs when inserted into them, and can stably and accurately perform insertion adjustment operations. It is an object of the present invention to provide a catheter that can be easily implemented at a low cost and that can also be appropriately manufactured with a small increase rate of outer diameter relative to inner diameter.

(Industrial application field) Medical catheters such as cardiac catheters, angiography catheters, and intravascular catheters.

(Prior art) For cardiac catheters, catheters for angiography, blood flow measurement, or fluid extraction, it is necessary that the tip part does not damage the inner wall surface of the blood vessel, and the insertion operation must be performed accurately. Therefore, a tube made of synthetic resin such as polyethylene or polyurethane is used, and the tip of the tube is made only of the material with a certain degree of flexibility, but other parts cannot be inserted. In order to improve operability during operation, a multilayer tube is used in which a braided material of stainless wire is interposed within the thickness of the tube layer, or a nylon core or other highly hard layer is attached inside.

In other words, the part on the tip side that is not multilayered has flexibility,
Moreover, in the multi-layered portion, the torque value is increased to make the insertion operation performed while contrasting using X-rays or the like more accurate.

(Problems to be Solved by the Invention) In the conventional catheters as described above, even if favorable characteristics can be obtained as a continuous catheter, the structure of the multilayered tube portion, which accounts for most of the catheter, is complicated and manufacturing is difficult. Therefore, it inevitably becomes expensive.

Naturally, the multilayered part described above requires a certain wall thickness, and since the outer diameter must be larger than the inner diameter, the diameter will be larger even if the material has the same injection characteristics.

"Structure of the Invention" (Means for Solving the Problems) A solid tube made of polytetrafluoroethylene is integrally connected to one end thereof, and is formed into a porous structure by fibrillation by stretching. A catheter characterized by having a tip portion that is more flexible than a tube.

(Function) By forming a porous tip at one end of a solid polytetrafluoroethylene tube by fibrillation by stretching, the tip is prevented from damaging the inner wall surfaces of blood vessels, the heart, etc. .

In addition, since the intermediate portion or the other end is made of the polytetrafluoroethylene solid tube described above, it has favorable torque properties, and allows an operator such as a doctor to easily and accurately push or rotate the tube from outside the body. Achieve proper and safe handling operations.

By integrally connecting the above-mentioned solid tube portion and the porous and flexible tip portion, the solid tube portion and the tip portion are firmly and stably connected, and can be manufactured from a single material. , and the inner and outer diameters are approximately the same, and the overall wall thickness is relatively thin.

Since it is entirely made of polytetrafluoroethylene, it is bioinert.

(Example) To explain a specific example of the invention according to the present invention as described above, as shown in the attached drawings, as shown in FIG. A porous Mi weave 2 made of the resin is formed on the tube 1, and a connector 3 or the like is attached to the proximal end of the tube 1.

The method for obtaining the catheter of the present invention as described above is as shown in FIG. As shown in FIG. 2(A), the tube 1 is stretched 2a, and by partially stretching 2a under temperature conditions depending on the material of each tube 1, the tube 1 becomes fibrillated and becomes porous. structure, and after this stretching process to make it porous, the same figure (B
), and then the middle portion of this porous portion 2b is cut to form the tip portion 2 as shown in FIG. 2(C). In specific manufacturing, the stretched portions 2a as described above may be alternately formed in the middle of unstretched portions during tube manufacturing. In any case, a catheter is obtained which is made flexible by making it porous and has a wall thickness that is solid between the tube 1 section and the distal end section 2. The porosity of the tip 2 obtained in this way is generally 30 to 9.
5%, preferably 60-90%, and the average pore size is 0.5%, preferably 60-90%.
The thickness is about 01 to 20 μm, preferably about 1 to 5 μm.

In addition, the device according to the present invention uses a polytetrafluoroethylene porous tube obtained by stretching in the opposite direction to that shown in FIG. 2 as a raw material, and as shown in FIG. Covering with a cover 4 made of a material with low thermal conductivity, such as ceramic or a material similar to it, is heated to a higher temperature than the firing temperature shown in FIG. Figure 3 (B)
By cutting the porous intermediate portion 5 as shown in the figure, a product having the porous portion as the tip portion 2 can be obtained.

In this case, the porosity of the tip 2 is the same as above, generally 30 to 95%, preferably 60 to 90%,
Average pore size is 0.01 to 20 μm, preferably 1 to 5 μm
It is.

Immediately after firing the solid tube obtained by extruding polytetrafluoroethylene paste as shown in FIG. 4, a tensile force is applied to one end of the tube 6 as shown in FIG. 4(B). By stretching (stretching) and making the one end porous, it is also possible to obtain a product with a flexible tip 2 as shown in FIG. 2(C). In this case, a product is obtained in which the porosity and average pore diameter due to the porous structure are the same as those shown in FIG. 2 or 3, and the tip portion 2 is a flexible portion.

In addition, a catheter containing a contrast agent can be manufactured by mixing a contrast agent powder such as barium sulfate into fine powder of polytetrafluoroethylene, or by a coagulation method, and the catheter can be properly contrasted with X-rays. can do. For example, the average particle size is 10 μm
A mixture of 20 to 70 wt% of the following contrast agent powder and 30 to 80 wt% of fine powder of polytetrafluoroethylene is made into a tube, and one end of the tube is stretched to make it porous. In this case, a preferable product is obtained in which the contrast agent powder is mainly collected in the micro nodules between the fibrillated Mi weaves.

In any case, the inner and outer diameter of the resulting product can be of any value, but in particular, those with an outer diameter of 1.5 to 3 m.
W, inner diameter is 1.0-1.8 ml, wall thickness is 0.3-0,
A product with a diameter of about 6 mm is practical, and compared to the conventional stainless steel wire braided structure described above, a product with a smaller outer diameter and an equivalent inner diameter can be obtained, making it more practical. The torque value in the tube part is about 3 to 7 times that of the flexible tip part (porous Mi weave), and the tip part 2 does not damage the inner wall of blood vessels, etc., and has good operability and can be used for X-rays, etc. The catheter can be imaged using the catheter, and a doctor or the like can easily push it forward or rotate it at hand, allowing for accurate use.

"Effects of the Invention" According to the present invention as explained above, the tip part is made flexible and does not damage the inner wall surfaces of blood vessels, the heart, etc., and moreover, it is easy to reach a predetermined position after insertion, and furthermore, to displace it. It is possible to provide a catheter that can accurately carry out pushing and rotation operations, and can be easily and inexpensively obtained from a single material without the need for a multilayer structure with internal materials such as stainless steel wire. The catheter has a comparatively large inner diameter compared to the diameter, which allows for smooth injection of contrast media, etc., and also has the advantages of being inert to the body and having little resistance to blood coagulation. Ori,
This invention has great industrial effects.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings illustrate the technical contents of the present invention, and FIG. 1 is a side view showing one example of a catheter according to the present invention, and FIG.
4 to 4 are explanatory diagrams showing step-by-step a method for manufacturing the solid tube portion and the flexible tip portion as one unit. In these drawings, 1 is a polytetrafluoroethylene tube, 2 is a porous U-weave tip, 2a is a stretched portion, 2a' is a porous portion, 2b is a porous tube, 3 is a connector, 4 is a cover, 5 is an intermediate portion, and 6 is a tube. Hana 4 l pisu

Claims (1)

[Claims] A solid tube made of polytetrafluoroethylene is integrally connected to one end of the solid tube, and is formed into a porous structure by fibrillation by stretching to form a tip portion that is more flexible than the solid tube. catheter.