JPH0838610A - Production of balloon catheter - Google Patents

Abstract

PURPOSE:To provide a process for production of a balloon catheter having no difference in level in the juncture of a balloon part and catheter tube which are connected by maintaining resilience in this juncture. CONSTITUTION:This process for production has a stage for fixing a fusion margin part 10 of the crosslinked polyolefin balloon part 5 to a fixing section 12 by a yarn-like fixing member 16, fusing this part by heating, then removing the fixing member 16 at the time of fusing the fusion margin part 10 to the catheter tube 2.

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 used in a procedure of inserting and dilating a stenotic portion of a heart artery causing myocardial infarction or the like.

[0002]

2. Description of the Related Art In a conventional balloon catheter, the work of attaching the balloon portion to the catheter tube is carried out by covering the fusion-bonding portion of the tube to be the balloon with the joining portion of the catheter tube containing the core and then using a heated die. It was heated by the sandwiching and was fused. However, in such a method, due to the sandwiching method with a mold, uneven thickness may occur in the fusion-bonded portion, and the fusion-bonding strength may be reduced. In addition, shrinkage may occur after fusion-bonding to make it hard. Therefore, there is a fear that the flexibility is lost and the operability is deteriorated.
Further, there may be a step between the catheter tube and the balloon fusion margin, and this step may be caught when the tube is housed inside the guiding catheter, which may cause inconvenience in terms of operability. It was Therefore, a balloon catheter aiming at solving such a difference in level is disclosed in JP-A-6-114109. In this publication, a metal tube is inserted and fixed in a state of being half exposed to the inside of the catheter tube, and the exposed end is covered with a balloon end so that the balloon end does not cover the catheter tube. Is to prevent the occurrence of.

[0003]

[Problems to be Solved] Although the step cannot be formed as described above, since the balloon portion and the catheter tube are fixed to the metal tube, a hard portion is partially formed, and the metal tube is inserted. It needs a certain amount of thickness,
It was difficult to apply it to a thin catheter. Further, it is necessary to insert and fix the metal tube into both the balloon portion and the catheter tube, which is extremely difficult to manufacture.

The present invention solves the above-mentioned problems of the prior art, and the balloon portion and the catheter tube are flexible at the joint portion, so that the both are firmly joined and there is no step in the balloon catheter. The purpose is to provide.

[0005]

[Means for Solving the Problems] The above-mentioned problems are described in the following (1) to
This is solved by the present invention, which is the manufacturing method described in (7). Further, it is solved by the present invention described in (8).

(1) The balloon portion has a fusion-bonding portion for fixing to the catheter tube, and when the fusion-bonding portion is fused to the fixing portion on the distal end side of the catheter tube, After fixing the fusion allowance portion to the fixing portion with a fixing member, heat fusion, further has a step of removing the fixing member, the balloon portion and the catheter tube is made of a compatible member, The method for producing a balloon catheter, wherein the fixing member is incompatible with the balloon portion and the catheter tube, or has a melting point higher than that of the balloon portion and the catheter tube.

(2) The fixing member is a filament, and in the fixing method, the fusion allowance portion of the balloon portion is covered with the fixation portion of the catheter tube, and then the fusion allowance portion is formed with the filamentous body. The method for producing a balloon catheter according to (1) above, which is performed so that the balloon catheter is tightly covered.

(3) The method for producing a balloon catheter according to the above (2), in which the filamentous body is wound while applying tension.

(4) The fixing method is as follows.
Furthermore, the manufacturing method of the balloon catheter as described in said (2) or (3) which covers with a heat-shrinkable tube, heat-shrinks, and is fixed.

(5) The balloon portion comprises polyethylene, polypropylene, ethylene-propylene copolymer, crosslinked polyethylene, crosslinked polypropylene, crosslinked ethylene-propylene copolymer, linear low density polyethylene, ethylene-
Being selected from the group of hexene copolymers, and
The material of the catheter tube is a polyolefin resin, a cross-linked polyolefin resin, especially polyethylene, polypropylene, ethylene-propylene copolymer,
The method for producing a balloon catheter according to any one of (1) to (4) above, which is selected from the group of crosslinked polyethylene, crosslinked polypropylene, crosslinked ethylene-propylene copolymer, and high density polyethylene.

(6) The method for producing a balloon catheter according to the above (4) or (5), wherein the heat-shrinkable tube is made of silicone.

(7) The method for producing a balloon catheter according to the above (2) to (6), wherein the filament is made of nylon.

(8) The catheter tube has a double tube structure of an outer tube and an inner tube, and the balloon portion has a tip fusion margin portion, an expansion portion that expands in diameter during expansion, and a rear end fusion margin portion. After the rear end fusion margin portion and the tip of the outer tube are fused, the tip fusion margin and the tip of the inner tube are fused, and
A method for producing a balloon catheter, which is carried out by the method (7).

[0014]

The balloon portion has a fusion-bonding margin portion for fixing to the catheter tube, and when the fusion-bonding margin portion is fused to the fixing portion at the tip of the catheter tube, the fusion-bonding margin portion is formed. Is fixed to the fixing portion with a fixing member, and then heat fusion is performed, and the state in which the balloon fusion margin portion is fixed by the fixing member is the same as that after the fusion because it includes a step of removing the fixing member. Since it is fused in a state, there is almost no change in the shape of the balloon fusion margin before and after fusion, and since the distal end is also fused while being pressed by the fixing member, the distal end is a catheter. It fuses with the tube and forms a state with almost no steps.

Further, since the fixing member is a filamentous material, by winding so as to uniformly cover the fusion-bonding margin portion, there is no unevenness in the fusion-bonding strength.

Furthermore, since the filamentous material is wound while being tensioned, a reliable fusion strength can be obtained when the fusion allowance portion and the catheter tube are fused.

Further, since the heat-shrinkable tube is further covered by the heat-sealing, the heating does not occur unevenly in the fusion-bonded portion, and uniform fusion can be achieved.

Further, the balloon portion has polyethylene, polypropylene, ethylene-propylene copolymer, crosslinked polyethylene, crosslinked polypropylene, crosslinked ethylene-propylene copolymer, linear low density polyethylene, ethylene-
It is selected from the group of hexene copolymers, and the material of the catheter tube is a polyolefin resin, a crosslinked polyolefin resin, particularly polyethylene, polypropylene, ethylene-propylene copolymer, crosslinked polyethylene, crosslinked polypropylene, Since it is selected from the group of cross-linked ethylene-propylene copolymer and high-density polyethylene, it shows compatibility when heated and exhibits high fusion strength.

Since the heat-shrinkable tube is made of silicone, the balloon portion and the catheter tube are not compatible and can be easily removed.

Further, since the filament is made of nylon, the balloon portion and the catheter tube are not compatible and can be easily removed.

The materials of the crosslinked polyolefin balloon portion and the catheter tube can be used by appropriately combining the above-mentioned materials. In this case, the temperature for fusing varies depending on the respective materials, but generally 1
20-160 degreeC is preferable. More preferably 1
20 to 150 ° C., particularly preferably 130 to 140
° C. If it exceeds 160 ° C., melting may proceed, which may lead to deterioration of strength or melting of the fixing member.
If it is lower than 0 ° C, melting may not occur, which is not preferable.
When the material for the cross-linked polyolefin balloon and the catheter tube are the same, the actual melting temperature is preferably about 5 to 15 degrees higher than the melting point of the material, provided that it does not exceed the melting point of the fixing member. Is. In consideration of this, it is preferable that the melting points of the materials of the cross-linked polyolefin balloon portion and the catheter tube and the melting point of the fixing member have a difference of about 20 to 30 degrees.

[0022]

【Example】

(Embodiment 1) Next, the production method of the present invention will be described in detail with reference to preferred embodiments.

FIG. 1 is an overall view (partial cross-sectional view) of a balloon catheter 1 particularly useful for PTCA manufactured according to the present invention.
Is. The balloon catheter 1 includes an outer tube 2 and an inner tube 3.
A catheter tube 4, which is a long tubular body having a heavy pipe structure,
It comprises a balloon portion 5 at the tip and a Y-shaped connector 18 at the base end. Among them, the connector 6 communicates with the inner pipe 3 and the connector 7 communicates with the outer pipe 2.

The balloon portion 5 is composed of an expanded portion 8, a tip fusion margin portion 9 and a rear fusion portion 10, and a rear fusion portion 10
Is fused and fixed to the fixing portion 12 at the tip of the outer tube 2 by the manufacturing method of the present invention described later. The tip fusion margin portion 9 is fixed to the tip portion 11 of the inner tube 3 by being bonded or fused.

A first lumen 21 is formed in the inner tube 3, and a second lumen 22 is formed between the inner tube 3 and the outer tube 2. The first lumen 21 is a lumen mainly for inserting a guide wire, injecting a drug solution into a blood vessel, measuring blood pressure, and the like. The second lumen 22 is a lumen serving as a fluid flow path for expanding the expansion section 8 and communicates with the inside of the expansion section 8.

X is formed on the outer peripheral surface of the inner pipe 3 covered with the expansion portion 8.
A marker 23 made of a radiopaque material (gold chip) is provided. Thereby, the position of the expansion portion 8 can be confirmed under fluoroscopy. FIG. 2 shows an intermediate view (cross-sectional view) of the step of fusion-fixing the rear end fusion-bonding margin portion 10 of the balloon portion 5 to the fixing portion 12 of the outer tube 2 described with reference to FIG. The manufacturing method will be described.

Inside the outer tube 2 made of high density polyethylene (HDPE) and having an outer diameter of 0.90 mm and an inner diameter of 0.75 mm, the outer diameter is approximately the same as the inner diameter (0.01 with respect to the inner diameter of the outer tube 2). Core metal 14 having a diameter of about 0.02 mm)
Is inserted so that it is exposed beyond the balloon portion fixing portion 12 of the outer tube 2. A balloon portion made of a cross-linked polyolefin resin (a linear low-density polyethylene (ethylene-hexene copolymer (C ₆ LLDPE) is used as a specific material) is used so as to cover the fixing portion 12. Part (inner diameter 0.93 to 0.96 mm, thickness about 0.075 m
m) Cover 10 Here, the expanded portion 8 of the balloon portion 5 is in a folded state, and the expanded portion 8 is protected from the heat of the hot air by covering the tube of the ethylene-tetrafluoroethylene copolymer (ETFE) or the polyimide tube. Since it is possible to prevent the expansion portion 8 from shrinking due to heat, it is preferable.

In this way, a fusion-bonding portion 15 in which the core metal 14, the fixing portion 12 of the outer tube 2, and the rear-end fusion-bonding margin portion 10 of the cross-linked polyolefin balloon 5 are sequentially laminated is completed.

Then, an appropriate tension (about 10 to 100 g) is applied to the outer periphery of the fusion-bonded portion 15 to make a nylon thread (diameter: 0.
Wrap 16 (about 01 to 0.05 mm). At this time, make sure to completely cover just before the end. Both ends of the nylon thread 16 are temporarily fixed with an instant adhesive.

As shown in FIG. 3 (cross-sectional view), the heat-shrinkable tube 17 made of silicone on the fusion-bonded portion 15 is covered.

Thereafter, hot air of a predetermined temperature (130 to 135 ° C., about 45 seconds) is applied from above the heat shrinkable tube 17,
The shrink tube is shrunk, and further heated and fused.

After being left at room temperature for cooling, the heat-shrinkable tube 1
7 is removed and then the nylon thread 16 is removed.

By going through such a process, FIG.
As shown in (cross-sectional view), the rear end fusional margin portion 10 is fused with the fixed portion 12 of the outer tube 2, and there is almost no step at the end portion,
It is possible to provide the fused portion 15 having high fusion strength.

Subsequently, the tip portion 11 of the inner pipe 3 and the tip fusion allowance portion 9 are fused by almost the same method. Figure 5 (cross section)
As shown in, a core having an outer diameter substantially the same as the inner diameter of the tip of the inner pipe 3 (specifically, high density polyethylene (HDPE)) 3 (outer diameter 0.65 mm, inner diameter 0.5 mm). After inserting the gold 19 so that the tip of the tip fusion allowance portion 9 is substantially aligned with the tip of the inner tube 3, it is similarly wound with a nylon thread 16 and the tip fusion allowance portion 9 is made into the tip portion 11.
Fixed to. After this, subsequently, as shown in FIG. 6 (cross-sectional view), a heat-shrinkable tube 17 is covered and heat fusion is performed. After cooling, the heat-shrinkable tube 17 that has shrunk is removed, and the nylon thread 16 is removed. Also here, it is preferable to cover the expanded portion 8 with the ETFE tube or the polyimide tube in order to protect the expanded portion 8 from the hot air during heating.

Subsequently, as shown in FIG. 7 (cross-sectional view), the fused tip portion 11 is cut so that the fused portion becomes about 2 mm, and a rounded portion 20 is formed at the tip.

Finally, the balloon catheter 1 can be manufactured by connecting the Y-shaped connector 18 having the connector 6 and the connector 7 so as to communicate with the inner tube 3 and the outer tube 2.

Further, the connector 7 is first connected to the base end of the outer tube 2, and the rear end fusion bonding margin 1 of the balloon portion 5 is attached to the front end of the outer tube 2.
After fusing 0, the tip of the inner tube 3 and the tip fusing margin 9 of the balloon portion 5 may be fused, and then the base end of the inner tube 2 and the connector 6 may be connected.

[0038]

EFFECT OF THE INVENTION The method for manufacturing a balloon catheter of the present invention is a method for manufacturing a balloon catheter having a balloon portion for expanding a blood vessel by being inserted into a stenosis site of a blood vessel. When fusing to the catheter tube, there is a step of fixing the fusing margin portion of the balloon portion to a fixing portion of the catheter tube with a fixing member, heating and fusing, and further removing the fixing member. The balloon part and the catheter tube are made of compatible members, and the fixing member is not compatible with the balloon part and the catheter tube, or the melting point of the balloon part and the catheter tube is higher. Therefore, the state in which the balloon fusion margin portion is fixed by the fixing member is fused in the same state as after fusion, so that the balloon fusion margin before and after fusion Eliminates hardening due to changes and shrinkage minute shape most, it is possible to maintain the flexibility, also, since the end portion is also fused in a state of being squeezed fixing member,
The end portion can be easily fused with the catheter tube to form a step-free state, does not bend even when inserted into a complicated and tortuous site such as a cardiovascular vessel, and does not damage the inner wall of the blood vessel.

Further, since the fixing member is a filament, it can be wound so as to uniformly cover the fusion allowance portion, so that there is no unevenness in the fusion strength and a stable expansion force can be obtained.

Furthermore, since the filamentous material is wound while applying tension, a reliable fusion strength can be obtained during fusion.

Further, since the heat-shrinkable tube is further covered by heat fusion, the heating is prevented from being unevenly generated in the fused portion, and uniform fusion can be achieved.

The material of the crosslinked polyolefin balloon portion and the catheter tube are compatible with each other, and the melting point of the fixing member is higher than that of the material of the crosslinked polyolefin balloon portion and the catheter tube. Therefore, there is an advantage that the temperature can be easily determined.

Since the heat-shrinkable tube is made of silicone, it has no compatibility with the balloon portion or the catheter tube and can be easily removed.

Further, since the filament is made of nylon, the balloon portion and the catheter tube are not compatible and can be easily removed.

[Brief description of drawings]

FIG. 1 is an overall view of a balloon catheter manufactured by the present invention.

FIG. 2 is a diagram showing an intermediate stage of a process of fusion-bonding and fixing a balloon portion to an outer tube.

FIG. 3 is a diagram showing a state in which a heat-shrinkable tube is covered on the fusion-bonded portion of the outer tube and the balloon portion.

FIG. 4 is a diagram showing a state after fusion of the outer tube and the balloon portion.

FIG. 5 is a diagram showing an intermediate stage of the process of fusion-bonding and fixing the balloon portion to the inner tube.

FIG. 6 is a diagram showing a state in which a heat-shrinkable tube is covered on the fusion-bonded portion of the inner tube and the balloon portion.

FIG. 7 is a diagram showing a state after fusion of the inner tube and the balloon portion.

[Brief description of reference numerals]

 1 ... Balloon catheter 2 ... Outer tube 3 ... Inner tube 4 ... Catheter tube 5 ... Balloon part 6, 7 ... Connector 8 ... Expansion part 9 ... Tip fusion Replacement part 10 ... Rear end fusion bonding part 11 ... Tip part 12 ... Fixed part 13 ... Space 14 ... Core bar 15 ... Fused part 16 ... Nylon thread 17. ..Heat-shrink tube 18 ... Y-shaped connector 21 ... First lumen 22 ... Second lumen

Claims (1)

[Claims] 1. The balloon portion has a fusion allowance portion for fixing to the catheter tube, and when the fusion allowance portion is fused to a fixing portion on the distal end side of the catheter tube, After fixing the dressing portion to the fixing portion with a fixing member,
A step of heating and fusing, and further removing the fixing member, wherein the balloon part and the catheter tube are made of compatible members, and the fixing member is not compatible with the balloon part and the catheter tube Or a melting point higher than the melting point of the balloon portion and the catheter tube.