JPH0314469B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a balloon catheter for indwelling in a blood vessel having an inflatable balloon attached to its tip, and particularly to a method for attaching the balloon.

[Conventional technology]

This type of intravascular balloon catheter is generally used to introduce the tip of the catheter into the blood vessel using an insertion device such as an introducer, and then indwell it at a predetermined site for measurement and treatment. It is.

However, with conventional balloon catheters, the outer diameter of the attached balloon (before expansion) is larger than the outer diameter of the catheter, and it protrudes outside, so when inserting it into a blood vessel, the insertion device There were problems such as the balloon getting stuck on the inner wall of attached check valves and other equipment, causing damage.

Therefore, it has been proposed to make the tip of the catheter smaller in diameter than the catheter size and attach a balloon thereon to make the diameter the same as the catheter size. However, in this case, the catheter can be inserted into the blood vessel using a sheath with the same diameter as the catheter size, reducing the burden on the blood vessel, but the balloon is larger than the outer diameter of the catheter tip at the upper end of the balloon. Because there is a step between the catheter tip and the catheter tip, there is a risk that the balloon will come into direct contact with the check valve installed at the insertion port of the blood vessel insertion device and be damaged. There is a problem in that it is easy to form.

As another method, a method has been proposed in which the boundary between the upper end of the attached balloon and the catheter tip is potted with adhesive or the like to smoothly connect the catheter tip and the balloon attachment surface.

However, in this case, although the problem of balloon damage mentioned above has been resolved, since the outer diameter of the device balloon is larger than the outer diameter of the catheter tip, it is necessary to use a sheath that matches the balloon diameter larger than the catheter size diameter. First, this increases the burden on the blood vessels, and since the potting part is not integrally molded with the same material, there remains the problem of peeling of the adhesive part, which completely eliminates the risk of indwelling the catheter in the blood vessel. It is not possible.

Furthermore, since this type of intravascular balloon catheter has an extremely small diameter, it has been extremely difficult to mass-produce the balloon in a structure that does not protrude from the outer diameter of the adjacent catheter.

[Problem that the invention seeks to solve]

This invention eliminates the risk of the attached balloon being damaged if it hits the check valve or other inner wall member of the blood vessel insertion device, alleviates thrombus formation near the balloon attachment part, and allows the sheath to be inserted with a diameter larger than the catheter diameter. There is no need to use
The present invention aims to provide a method for attaching a balloon to a balloon catheter with a structure that places less burden on blood vessels.

[Means for Solving the Problems] As a means for solving the above-mentioned problems, the present invention provides the following method. An annular groove is formed adjacent to the outer surface of the tube body along the circumferential direction and over a predetermined length in the axial direction, and further has an internal passage for balloon inflation and deflation that opens at the bottom of the annular groove. Prepare a catheter body, insert rod-like bodies with an outer diameter approximately equal to the inner diameter of the passages into both internal passages to secure the inner diameter of the internal passages, and then attach one end of the balloon tube to the tip of the catheter body. The balloon tube was placed on one end of the annular groove, one end of the balloon tube was fixed to the one end of the annular groove with adhesive or thread, and the balloon tube was then inserted into the annular groove while being turned over. Thereafter, the method includes a step of fixing the other end of the balloon tube onto the other end of the annular groove by wrapping adhesive or thread, so that both ends of the attached balloon tube are attached to the catheter body. The present invention provides a method for manufacturing a balloon catheter, characterized in that a substantially smooth continuous surface is formed with the distal end portion and the rear portion of the catheter body to which the balloon tube is bonded.

The smooth continuous surface may be formed by embedding a potting material in the boundary between the balloon tube and the tip of the catheter body or the rear portion of the balloon tube attached. Also, wrap a wrapping thread around the boundary between the balloon tube and the balloon tube connecting rear portion of the catheter body with appropriate tension, and embed the balloon tube and the wrapping thread into the tube body of the catheter body. You can also do it like this.

[Effect]

According to the method of the present invention, a predetermined balloon can be attached to the distal end of the catheter body so as to form a smooth continuous surface with the catheter body near the balloon attachment part, so that when inserting the catheter,
It is possible to reduce the risk of the balloon being damaged by getting caught in a check valve or the like of a blood vessel insertion device, or the formation of a blood clot at the balloon attachment point.

〔Example〕

Next, a method for attaching a balloon to a balloon catheter of the present invention will be explained.

First, the distal end portion 1a of the catheter body 1 is processed to form the catheter distal end shape as shown in FIG. 2a. First, as shown in Figure 3, the French size is 4 or 5, which is 4Fr to 8Fr.
A catheter body 1 made of polyvinyl chloride is prepared, and as shown in FIG. Insert metal rods 9 and 10. In order to prevent distortion during machining, the catheter body 1 is
Insert the same polyvinyl chloride rods 11 and 12. In this state, the tip part of the catheter body 1 is heated and formed using a glass mold or a metal mold to a predetermined length (i.e., a length that includes the part where the balloon is to be attached and the part where the tip is to be processed) with a thin diameter. (See Figure 4). This processing can be similarly performed by ultrasonic processing or high frequency processing using a metal mold.

Next, as shown in FIG. 5, a stainless steel tubular body 13, which can be divided into two in the longitudinal direction, is inserted into the reduced diameter portion 14 so as to cover the portion where the balloon is to be attached. Next, the distal end portion 15 exposed from the upper end of the tubular body 13 is subjected to heat molding, ultrasonic processing, or high frequency processing using a glass mold or metal mold having a shape corresponding to the catheter distal end portion 1a shown in FIG. 2a. After processing, a shape approximately corresponding to that of FIG. 2a, that is, a tip 1
A catheter main body 1 is obtained, which is a flexible tube body having a substantially convex surface a and an annular groove 1b formed along the circumferential direction adjacent to the distal end portion 1a. Next, after dividing and removing the tubular body 13, the metal rods 9 and 10 are taken out from the tip of the catheter body and passed through the pressure measurement cavity and the balloon expansion cavity 1d.

Next, the peripheral edge 1e of the catheter tip 1a that is in contact with the balloon attachment part (corresponding to the annular groove 1b in FIG. 2a) is heated, rounded using high frequency or ultrasonic waves, and surface treated with tetrahydrofuran solution to make it smooth. Finish in a curved shape.

Next, make sure that the pressure measurement cavity 1 is not deformed.
Metal or heat-resistant hard plastic pipes or rods 7 and 8 having approximately the same diameter are inserted into the balloon expansion cavity 1d and the balloon expansion cavity 1d (see FIG. 2d).
Next, a balloon tube 2 made of latex rubber and open at both ends is inserted so that one end thereof covers the distal end 1a, as shown in FIG. 2b. Next, one end of the balloon tube 2 is fixed by wrapping the thread 3 around the annular groove 1b as shown in FIG. 2c. Note that instead of the thread 3, an adhesive may be used for fixing, or the thread 3 may be wrapped around the thread 3 and adhesive may be applied over it for fixation. The material for the winding thread 3 may normally be made of plastic such as nylon. As the adhesive, a cyanoacrylate adhesive is preferred.

Next, as shown in FIG. 2d, in order to fit the other end of the balloon tube 2 into the catheter body 1, the balloon tube 2 is turned over and introduced toward the catheter body 1. Then, as shown in FIG. 2e, the other end of the balloon tube 2 is fixed to the annular groove 1b via the thread 3 or adhesive, and furthermore, a gap formed between this fixed part and the catheter body 1 is fixed to the annular groove 1b. A potting agent 16 is applied to the stepped portion.
In this case, the potting agent 16 is preferably one based on urethane, epoxy, or silicone. Finally, the pipes or rods 7, 8 are taken out. As a result, a balloon catheter as shown in FIG. 1 can be obtained without deforming the pressure measurement cavity 1c and the balloon expansion cavity 1d. This fixation of the balloon tube 2 is performed when the outer diameter of the attached balloon tube 2 is not expanded.
This is done in consideration of making it equal to or smaller than the maximum outer diameter l of a. Therefore, the groove 1b is formed sufficiently deep considering the mounting thickness of the balloon tube 2.

In the above embodiment, the potting agent 16 was embedded in the step formed between the other end attachment part of the balloon tube 2 and the catheter body 1 to flatten this attachment part, but the wrapping thread 3 The other end of the balloon tube 2 and the thread 3 are embedded in the catheter body 1,
The potting agent 16 may be omitted by fixing with adhesive to flatten this attachment portion. An example of the tension in thread 3 in this case is
Approximately 5 to 50 g of 20° nylon 6 thread is appropriate.

Note that thermoplastic resins such as polyolefin, ethylene-vinyl acetate copolymer, polyester, polyvinyl chloride, polyurethane, fluorine resin, and nylon are generally used as the material for the catheter body.

In addition to latex, the material for balloon 2 is
It can be appropriately selected from elastic materials such as polyurethane and silicone rubber.

To explain how to use this balloon catheter, as shown in FIG. 4 and gradually introduced into the blood vessel 5.

In this operation, since the outer diameter of the balloon 2 is equal to or smaller than the outer diameter of the distal end 1a of the catheter body 1, a check valve (not shown) disposed at the insertion port 4a of the blood vessel insertion device 4, etc. There is no risk of getting hit. Furthermore, since the inner diameter of the blood vessel insertion device 4 does not need to be larger than the diameter of the catheter, the burden on the blood vessel is also reduced. The distal end portion 1a of the catheter main body 1 that has reached the blood vessel has a substantially flat convex shape (or disk shape), so that it can be introduced to a predetermined position within the blood vessel 5 without stimulating the blood vessel wall.

Next, carbon dioxide gas is passed through the second internal passage 1d.
By introducing another fluid into the balloon 2, the balloon 2 can be expanded to a predetermined size as shown in FIG. 7, and the catheter can be introduced to a predetermined position. In this case, since the edge portion 1e of the catheter body 1 has a smooth curved surface, the expansion of the balloon 2 is performed smoothly without being hindered by this portion, and a bulge having a well-symmetrical shape is obtained. When you want to deflate balloon 2 again, use the second
The fluid inside the balloon 2 may be discharged through the internal passage 1d.

[Effects of the Invention] As detailed above, according to the method for attaching a balloon to a balloon catheter according to the present invention, the attached balloon has a smooth continuous structure with no difference in level between the attached balloon and the outer diameter of the catheter body around the attachment portion. Because it has a flat surface, when inserting the catheter, it can be handled smoothly without causing problems such as getting caught in the check valve of the blood vessel insertion device and being damaged. Thrombus formation is alleviated. Furthermore, since there is no need to use a sheath that is thicker than the catheter diameter, the burden on blood vessels can be reduced. Furthermore, when moving the balloon in a deflated state within a blood vessel, the area around the balloon attachment part forms a smooth, continuous surface, so there is less irritation to the inner wall of the blood vessel, and the balloon can be moved safely and smoothly through the blood vessel. It has a great effect.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the distal end portion of a balloon catheter according to an embodiment of the present invention, and FIGS. 2a to 2e show a method of attaching the balloon to the catheter body of the balloon catheter of FIG. 1 in the order of steps. Figures 3 to 5 are perspective views sequentially showing the steps of processing the tip of the catheter body, Figure 6 is a schematic diagram for explaining how to use the balloon catheter, and Figure 7 is the balloon catheter of Figure 1. It is a sectional view showing an expanded state. In the figure, 1... Catheter body, 1a... Tip part, 1b... Annular groove, 1c... Pressure measurement cavity, 1
d... Balloon expansion cavity, 1e... Edge, 2...
...Balloon tube, 3... Attachment thread, 4... Blood vessel insertion device, 5... Blood vessel, 6... Balloon catheter, 7, 8... Pipe or rod, 9, 10... Metal rod, 11, 12... ...Polyvinyl chloride rod, 13
...Stainless steel tubular body, 14...Narrowed diameter portion, 1
5... Part to be processed at the tip, 16... Potting agent.

Claims (1)

[Scope of Claims] 1. Adjacent to the distal end of a flexible tube having at least one internal passageway opening at the distal end, a predetermined portion is provided on the outer surface of the tube body along its circumferential direction and in its axial direction. A catheter body is prepared, which has a long annular groove formed therein, and an internal passage for balloon inflation and deflation that opens at the bottom of the annular groove, and a rod-shaped body having an outer diameter approximately equal to the inner diameter of the passage is provided in both internal passages. is inserted to secure the inner diameter of the internal passage, and then one end of the balloon tube is placed on one end of the annular groove at the distal end of the catheter body, and one end of the balloon tube is wrapped with adhesive or thread. The balloon tube is fixed to one end of the annular groove by attaching, and then the balloon tube is turned over and inserted into the annular groove, and then the other end of the balloon tube is placed on the other end of the annular groove with adhesive or thread. The method includes a step of fixing by winding, so that both ends of the attached balloon tube form a substantially smooth continuous surface with the distal end of the catheter body and the adhesive rear part of the balloon tube of the catheter body. A method for manufacturing a balloon catheter, characterized in that: 2 Formation of a substantially smooth continuous surface at the connection between both ends of the balloon tube and the catheter body is achieved by embedding a potting material at the boundary between the balloon tube and the tip of the catheter body or the adhesive rear part of the balloon tube. The manufacturing method according to claim 1, characterized in that the manufacturing method is carried out by: 3. To form a substantially smooth continuous surface on the surface of the connection between the rear part of the balloon tube attachment and the catheter body, wrap the thread around this boundary area with an appropriate tension, and then wrap the thread around the balloon tube. 2. The manufacturing method according to claim 1, wherein the manufacturing method is carried out by embedding it in a tube body of a catheter body.