JPH0515604A - Production of balloon catheter - Google Patents

Abstract

PURPOSE:To smooth handling and to relieve the formation of a thrombosis around a balloon by adopting the constitution in which both ends of a tube for the balloon form a plane surface with the front end of a catheter body and the bonded rear end of the tube. CONSTITUTION:The front end 1a of the flexible tube having internal passages 1d, 1c for balloon expansion and pressure measurement is formed as a projecting surface shape and an annular groove 1b opened with the internal passage 1d for balloon expansion is formed in the bottom. One end of the tube 2 for the balloon is fixed to one end of the annular groove 1b by an adhesive or winding of yarn at the front end of the catheter body 1 and the other end of the tube 2 for the balloon is fixed onto the other end of the annular tube 1b by the adhesive or the winding of the yarn while turning over the tube 2 for the balloon. Both ends of the tube 2 for the balloon form the smooth surface with the front end of the catheter body 1 and the bonded rear part of the tube for the balloon in this way and, therefore, the damage of the balloon at the time of the insertion of the catheter and the formation of the thrombosis in the balloon mounting part are relieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a balloon catheter for indwelling in a blood vessel having an expandable and contractible balloon attached to its tip, and more particularly to a method of attaching the balloon.

[0002]

2. Description of the Related Art In a balloon catheter for indwelling in a blood vessel of this type, the tip of the catheter is introduced into the blood vessel by using an insertion instrument such as an introducer, and then the indwelling catheter is placed in a predetermined site for measurement and treatment. Is common.

However, in the conventional balloon catheter, the outer diameter (before dilation) of the attached balloon is larger than the outer diameter of the catheter, and the balloon is in a state of protruding to the outside. There was a problem that the balloon was caught on the inner wall of the check valve and other devices attached to the insertion device and was damaged.

Therefore, it has been proposed to make the tip of the catheter thinner than the diameter of the catheter and attach a balloon on the diameter to make it the same as the diameter of the catheter. However, in that case, the catheter can be inserted into a blood vessel by using a sheath or the like having the same diameter as the catheter size, and the burden on the blood vessel can be reduced, but the balloon is larger than the outer diameter of the catheter tip at the upper end of the balloon, Since there is a step between the tip of the catheter and the balloon, there is a risk that the balloon will come into direct contact with the check valve etc. installed at the insertion port of the blood vessel insertion instrument and damage the balloon.
There is a problem that thrombus is likely to be formed in this step portion.

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

However, in this case, although the above-mentioned problem of balloon damage is solved, since the device balloon outer diameter is larger than the catheter tip outer diameter, a sheath adapted to the balloon diameter larger than the catheter size diameter is used. This will increase the burden on the blood vessel, and since the potting portion is not integrally molded with the same material, the problem of peeling off the adhesive portion remains, and the risk of catheter indwelling in the blood vessel remains. It cannot be completely removed.

Further, since the balloon catheter for indwelling in a blood vessel of this kind has an extremely small diameter, it is extremely difficult to mass-produce the balloon in a structure which does not protrude from the outer diameter of the adjacent catheter.

[0008]

SUMMARY OF THE INVENTION The present invention eliminates the risk of the attached balloon being damaged by being caught by the check valve or other inner wall member of the blood vessel inserting instrument, and mitigating thrombus formation in the vicinity of the balloon attachment portion. In addition, it is an object of the present invention to provide a balloon attachment method for a balloon catheter having a structure that does not require the use of a thick sheath that is one size larger than the catheter diameter at the time of insertion and has a small burden on the blood vessel.

[0009]

The present invention provides a means for solving the above-mentioned problems by the following method, that is, a flexible tube balloon having at least two internal passages including a balloon inflation internal passage. The process of reducing the diameter of the tip part including the part to be mounted, and inserting the tubular split mold into this diameter-reduced part with the tip of the part exposed, and then shaping this tip to the convex shape. A step of forming an annular groove along the circumferential direction of the flexible tube and at the bottom of which an inner passage for balloon inflation is opened, and inserting a rod-shaped body having an outer diameter substantially equal to the inner diameter of the passage into the both inner passages. By securing the inner diameter of the internal passage, and installing one end of the balloon tube at one end of the annular groove at the tip of the catheter body, and wrapping one end of the balloon tube with an adhesive or a thread. The Fixing to one end of the annular groove, and then inserting the balloon tube into the annular groove while turning it over, and then wrapping the other end of the balloon tube on the other end of the annular groove with an adhesive or thread. And a step of taking out the rod-shaped body,
A method of manufacturing a balloon catheter, characterized in that both ends of the thus mounted balloon tube form a substantially smooth continuous surface with the distal end portion of the catheter body and the balloon tube adhesion rear portion of the catheter body. Is provided.

The smooth continuous surface may be formed by embedding a potting material at the boundary between the balloon tube and the distal end of the catheter body or the balloon tube rear bonding portion. The balloon thread is wrapped around the boundary between the balloon tube and the balloon tube connection rear portion of the catheter body with appropriate tension so that the balloon tube and the winding thread are embedded in the tube body of the catheter body. You can also

[0011]

According to the method of the present invention, a predetermined balloon can be attached to the tip of the catheter body so as to form a smooth continuous surface with the catheter body near the balloon attachment portion. It is possible to alleviate damage such as catching on a check valve or the like of the insertion instrument, or formation of thrombus at the balloon attachment portion.

[0012]

EXAMPLES Next, a method of attaching the balloon of the balloon catheter of the present invention will be described. First, the tip portion 1a of the catheter body 1 is processed to have a catheter tip shape as shown in FIG. First, as shown in FIG. 7, a French size 4Fr to 8Fr size 4 is used.
Alternatively, a polyvinyl chloride catheter body 1 having five lumens is prepared, and as shown in FIG. 7, in order to allow them to remain as internal passages in the pressure measurement lumen 1c and the balloon expansion lumen 1d, Insert metal rods 9 and 10, respectively. The same rod 1 made of polyvinyl chloride as that of the catheter body 1 is provided in the inner cavity to prevent distortion during processing.
Insert 1 and 12. In this state, a distal end portion of the catheter body 1 is thinned to a predetermined length (that is, a length including a balloon attachment planned portion and a tip processed portion ahead thereof) by heat molding using a glass mold or a metal mold. (See FIG. 8). This processing can be similarly performed by ultrasonic processing or high frequency processing using a metal mold.

Next, as shown in FIG. 9, the tubular portion 13 made of stainless steel, which can be divided into two in the longitudinal direction, is fitted into the reduced diameter portion 14 so as to cover the portion to be attached with the balloon. Then, the tip end processing portion 15 exposed from the upper end of the tubular body 13 is heated or ultrasonically processed or high frequency processed using a glass mold or a metal mold having a shape corresponding to the catheter tip 1a shown in FIG. 2 has a shape substantially corresponding to that of FIG. 2, that is, the tip portion 1a has a substantially convex shape, and an annular groove 1b is formed adjacent to the tip portion 1a along the circumferential direction. A catheter body 1 made of a flexible tube is obtained. Next, after the tubular body 13 is divided and removed, the metal rods 9 and 10 are taken out from the tip of the catheter main body, and the pressure measuring cavity and the balloon expansion cavity 1d are penetrated.

Next, the peripheral edge 1e which is in contact with the balloon mounting portion (corresponding to the annular groove 1b in FIG. 2) of the catheter tip portion 1a is subjected to heat molding, R processing by ultrasonic wave or high frequency, and surface treatment by tetrahydrofuran solution. Finish into a smooth curved surface.

Next, a pipe or rod 7 made of metal or heat-resistant hard plastic having substantially the same diameter as that of the pressure measuring cavity 1c and the balloon expanding cavity 1d so that the inner cavity is not deformed.
8 are inserted (see FIG. 5). Next, a balloon tube 2 made of latex rubber and having openings at both ends is inserted so that one end thereof covers the distal end portion 1a, as shown in FIG. Next, one end of the balloon tube 2 is wound around the annular groove 1b as shown in FIG. An adhesive may be used instead of the thread 3 to fix the thread 3.
Alternatively, the adhesive may be applied and fixed from above. As a material for the winding thread 3, a material made of plastic such as nylon can be usually used. A cyanoacrylate-based adhesive is preferable as the adhesive.

Next, as shown in FIG. 5, the balloon tube 2 is introduced toward the catheter body 1 by turning it over so that the other end of the balloon tube 2 is fitted into the catheter body 1. Then, as shown in FIG. 6, the other end of the balloon tube 2 is similarly fixed to the annular groove 1b via a thread 3 or an adhesive, and a step formed between the fixing portion and the catheter body 1 is also performed. The potting agent 16 is applied to the area. In this case, the potting agent 16 is preferably urethane, epoxy or silicone type. Finally, the pipes or rods 7, 8 are removed. As a result, the balloon catheter as shown in FIG. 1 can be obtained without deforming the pressure measurement cavity 1c and the balloon expansion cavity 1d. The fixation of the balloon tube 2 is performed in consideration of the outer diameter l of the attached balloon tube 2 being equal to or smaller than the maximum outer diameter l of the distal end portion 1a of the catheter body 1 when the balloon tube 2 is not expanded. .. Therefore, the groove 1b
Is formed sufficiently deep in consideration of the attachment thickness of the balloon tube 2.

In the above embodiment, the balloon tube 2 is used.
The potting agent 16 was embedded in the step formed between the other end mounting portion and the catheter body 1, and the mounting portion was flattened. The other end of the tube 2 and the thread 3 may be embedded in the catheter body 1 and fixed with an adhesive to flatten the mounting portion, and the potting agent 16 may be omitted. In this case, as an example of the tension applied to the thread 3, a nylon 6 thread of 20 degrees is preferably about 5 to 50 g.

The material of the catheter body is polyolefin, ethylene-vinyl acetate copolymer, polyester, polyvinyl chloride, polyurethane, fluorine resin,
Thermoplastic resins such as nylon are generally used.

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

Explaining the method of using this balloon catheter, as shown in FIG. 10, first, a blood vessel insertion instrument 4 (for example, an indwelling needle or introducer) is inserted into a blood vessel 5, and then a balloon catheter 6 is inserted into this blood vessel. It is inserted into the device 4 and gradually introduced into the blood vessel 5.

In this operation, since the balloon 2 has a diameter equal to or smaller than the outer diameter of the distal end portion 1a of the catheter body 1, a check valve (not shown) provided at the insertion port 4a of the blood vessel insertion instrument 4 or the like is provided. ), Etc. Furthermore, since it is not necessary to make the inner diameter of the blood vessel insertion device 4 larger than the catheter diameter, the burden on the blood vessel is reduced. The distal end 1a of the catheter body 1 that has reached the inside of the blood vessel has a substantially flat convex shape (or disk shape), so that it can be introduced to a predetermined position inside the blood vessel 5 without stimulating the blood vessel wall.

Next, carbon dioxide gas and other fluids are introduced into the balloon 2 through the second internal passage 1d to expand the balloon 2 to a predetermined size as shown in FIG. Can be introduced up to a position.
In this case, since the edge portion 1c of the catheter body 1 has a smooth curved surface, the expansion of the balloon 2 is smoothly performed without being obstructed at this portion, and a bulge having a good symmetry is obtained. When it is desired to deflate the balloon 2 again, the fluid inside the balloon 2 may be discharged through the second internal passage 1d.

[0023]

As described above in detail, according to the method for attaching a balloon of the balloon catheter of the present invention, the attached balloon has a smooth continuous surface without a step between the balloon and the outer diameter of the catheter body around the attaching portion. Since it is a flat surface, it is possible to facilitate the handling operation without causing problems such as being caught by the check valve of the blood vessel insertion device and being damaged when the catheter is inserted. Formation is moderated. Furthermore, since it is not necessary to use a sheath thicker than the catheter diameter, the burden on the blood vessel can be reduced. Furthermore, when moving the balloon inside the blood vessel in a deflated state, since the periphery of the balloon attachment part forms a smooth continuous surface, there is little irritation on the inner wall of the blood vessel and it is possible to move safely and smoothly in the blood vessel. Produce an effect.

[Brief description of drawings]

FIG. 1 is a sectional view showing a distal end portion of a balloon catheter according to an embodiment of the present invention.

FIG. 2 is a side view showing a method of attaching a balloon to a catheter body of the balloon catheter of FIG.

3 is a side view showing a method of attaching a balloon to a catheter body of the balloon catheter of FIG.

4 is a side view showing a method of attaching a balloon to a catheter body of the balloon catheter of FIG.

5 is a side view showing a method of attaching the balloon to the catheter body of the balloon catheter of FIG.

6 is a side view showing a method of attaching a balloon to a catheter body of the balloon catheter of FIG.

FIG. 7 is a perspective view showing a distal end processing step of the catheter body.

FIG. 8 is a perspective view showing a distal end processing step of the catheter body.

FIG. 9 is a perspective view showing a step of processing the tip of the catheter body.

FIG. 10 is a schematic diagram for explaining a method of using a balloon catheter.

11 is a cross-sectional view showing a state where the balloon catheter of FIG. 1 is expanded.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Catheter main body 1a ... Tip part 1b ... Annular groove 1c ... Pressure measuring cavity 1d ... Balloon expansion cavity 1e ... Edge 2 ... Balloon tube 3 ... Mounting thread 4 ... Blood vessel insertion device 5 ... Blood vessel 6 ... Balloon catheter 7 ... Pipe or rod 8 ... Pipe or rod 9 ... Metal rod 10 ... Metal rod 11 ... Rod 12 ... Rod 13 ... Stainless steel tubular body 14 ... Thinning portion 15 ... Tip processing portion 16 ... Potting agent

Claims (1)

Claim: What is claimed is: 1. A step of reducing the diameter of a distal end portion of a flexible tube having at least two internal passages including the balloon inflation internal passage, the distal end portion including a balloon mounting portion. A tubular split mold is inserted into the liquefied portion with its tip end exposed, and then this tip end is shaped into a convex shape, and along the circumferential direction of the flexible tube, and at the bottom, the inside for balloon inflation. A step of forming an annular groove with an open passage; a step of inserting a rod-shaped body having an outer diameter substantially equal to the inner diameter of the passage into each of the inner passages to secure the inner diameter of the inner passage; and a tip of the catheter body. Installing one end of the balloon tube on one end of the annular groove, and fixing one end of the balloon tube to the one end of the annular groove by winding an adhesive or a thread, and then turning the balloon tube inside out. While being inserted into the annular groove, the method includes a step of fixing the other end of the balloon tube on the other end of the annular groove by winding an adhesive or a thread, and a step of taking out the rod-shaped body. A balloon characterized in that both ends of the attached balloon tube form a substantially smooth continuous surface with the distal end portion of the catheter body and the rear portion of the catheter body bonded to the balloon tube. A method for manufacturing a catheter.