JPH0994296A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a catheter to properly follow bent blood vessels by providing for its construction a plastic inner tube, a coil wound on the outside of the inner tube with the coil tension higher at the base section than at the leading section, and an outer coil wound on the outside of the coil. SOLUTION: A catheter 1 is built of a tube and hub. The tube is approximately 1500mm long, and comprises an inner tube 4, coil 5, and outer tube 6, and has a platinum-made marker 7 buried at its leading edge 9 for pinpointing the position of the edge 9. For the formation of the coil 5, a stainless steel flat wire is wound, at a coil tension of 2-6kg for approximately 1300mm measured from the base side at a pitch of 0.5mm, then at a coil tension of not higher than 2kg for example at 0.5kg up to the vicinity of the leading edge 9 with the pitch kept constant at 0.5mm. The flat wire is provisionally fixed in the vicinity of the leading edge 9, and then is cut. A hydrophilic coating is applied to the inner and outer walls of the catheter as required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter used for intravascular treatment diagnosis, and to a catheter having a small diameter used for diagnostic treatment of a complicated tortuous blood vessel such as a blood vessel in the brain or abdomen.

[0002]

2. Description of the Related Art In recent years, a catheter is used for diagnostic treatment of a portion of a brain or abdomen where blood vessels are thin and meandering. The physical properties required for the catheter used at that time are rigidity on the base side that facilitates insertion into the blood vessel at the time of hand operation, or pressureability, and a thin bent blood vessel, and the catheter is inserted before it. Flexibility to follow the guide wire and not damage the blood vessel is required.

As a catheter which achieves both of these two physical properties, Japanese Patent Publication No. 44555/1992 has an inner tube and an outer tube which are double tubes, and the base (hand) side is made of a hard inner tube and a soft outer tube. There is disclosed a catheter in which the tip side is made only of a soft outer tube to make the base side rigid and the tip side soft.

Further, a catheter has been developed in which the base portion is formed of a hard material and the distal end side is formed of a flexible material, and the both are melted or bonded.

Further, in order to enhance the kink prevention effect,
A catheter having a coil from the proximal end to the distal end, a highly rigid layer covering the proximal end side, and a flexible outer layer covering the entire length has also been developed.

[0006]

[Problems to be Solved by the Invention] However, Japanese Patent Publication No. 4-4
Since the catheter of No. 4555 has a flexible tip, the transmission of longitudinal force was insufficient, leading to a decrease in insertion performance. Further, since it is soft, it may be inferior in kink resistance. Further, there is a problem that kinking is likely to occur because the hardness of the base end portion and the hardness of the tip end portion change abruptly. In contrast to these problems of easy kink, a catheter having a coil from the distal end to the proximal end does not easily cause kink, but the proximal end has a triple tube structure including the coil, and There may be a step between the base and the base end. In addition, there is a problem that the coil is exposed inside and there are many irregularities, so that the embolization material used for the treatment of a cerebral aneurysm is poorly inserted.

[0007]

Therefore, the present invention has the following configurations (1) to (10) in order to solve the above problems.

(1) An inner tube made of synthetic resin, a coil provided or embedded on the outer side of the inner tube, and an outer tube made of synthetic resin provided on the outer side of the coil. Is a catheter in which the proximal side is higher than the distal side.

(2) The winding tension of the coil is about 2 at the base end side.
The catheter according to (1) above, wherein the catheter has a weight of ˜6 Kg and a tip side of less than about 2 Kg.

(3) The catheter according to (1) or (2), wherein the coil winding tension between the proximal end side and the distal end side gradually changes.

(4) The catheter according to any one of (1) to (3) above, wherein the inner surface of the catheter is coated with a hydrophilic substance.

(5) The catheter according to any one of (1) to (4) above, wherein the outer surface of the catheter is coated with a hydrophilic substance.

(6) The coil is made of stainless steel, titanium,
The catheter according to any one of (1) to (5) above, which is selected from the group consisting of iron, tungsten and boron.

(7) The catheter according to any one of the above (1) to (6), wherein the coil on the distal end side has a coil pitch that increases as it goes to the distal end.

(8) The catheter according to any one of (1) to (7) above, wherein the coil on the distal end side is annealed to improve flexibility.

(9) The synthetic resin inner tube is selected from the group consisting of polyurethane, tetrafluoroethylene, nylon elastomer, polyethylene, polyethylene elastomer, polyester, polyester elastomer, and fluororesin. The catheter according to any one of the above.

(10) The catheter according to any one of (1) to (9), wherein the inner tube made of synthetic resin and the outer tube are made of the same synthetic resin material.

Since the catheter of the present invention has the above-mentioned constitution (1) or (2), since the coil is provided over the entire length of the catheter, it is excellent in kink resistance, pushability and torque transmission. . Furthermore, since the coil winding tension is weaker on the tip side than on the base side, the flexibility on the tip side is higher than on the base side,
Even if it is introduced into a bent blood vessel, the followability is improved. Here, if the winding tension on the base end side is less than a, the rigidity on the base end side becomes small and it is too flexible, so the operability at hand becomes very poor, and if it exceeds b, the rigidity becomes large and it is too hard. When inserting a blood vessel, there is a risk that the coil will be hindered and the coil will press and crush the inner tube. Further, when the winding tension on the distal end side exceeds d, the flexibility is lowered, and the distal end portion of the catheter cannot follow the bent blood vessel or the guide wire.

Further, the catheter of the present invention has the above (3).
With this configuration, since the winding tension of the coil gradually changes from the distal end side to the proximal end side, there is no rapid change in the rigidity of the catheter, and thus kink is less likely to occur.

Further, the catheter of the present invention has the above (4)
With this structure, the inner surface is hydrophilic, so that friction with the guide wire is reduced and operability with the guide wire is improved.

Further, the catheter of the present invention, having the above-mentioned constitution (5), is excellent in antithrombogenicity because the outer surface is coated with the hydrophilic substance.

Since the catheter of the present invention is made of the material of the above (6), the elongation of the material itself is small and the tension wound in the initial stage can be maintained.

The catheter of the present invention has the above (7).
Alternatively, by adopting the configuration of (8), the flexibility of the tip becomes higher and the followability to the meandering blood vessel becomes better.

Further, the catheter of the present invention has the above (9)
By adopting the above constitution, a catheter having high kink resistance can be provided without being crushed by the coil winding tension, the outer surface processing characteristics are improved, and the coating of the hydrophilic polymer is facilitated.

The catheter of the present invention has the above (1)
By adopting the configuration of 0), since the synthetic resin inner tube and the synthetic resin outer tube are partially compatible and the coil can be embedded in the synthetic resin, the coil tension is maintained for a long period of time. be able to. The coil may be embedded in the inner tube.

[0026]

EXAMPLES Next, the present invention will be described in detail based on examples.

[0027]

Example 1 FIG. 1 shows an overall image of a catheter of Example 1, and FIG. 2 is a partial sectional view of Example 1.

The catheter 1 of the present invention comprises a tubular body 2 and a hub 3. The tubular body 2 has a total length of 1500 mm and comprises an inner tube 4, a coil 5 and an outer tube 6. The inner tube 4 has an inner diameter of 0.4 mm, the thickness is 0.2 mm, the coil 5 has a thickness of 0.1 mm, a width of 0.5 mm, and the outer tube has a thickness of 0.1 mm.
It is. A coil-shaped platinum marker 7 having a high X-ray contrast property is embedded in order to easily confirm the position of the tip 9 of the tubular body. The hub 3 is connected to the base end 10, and the inner cavity of the hub 3 communicates with the lumen 8 of the inner tube 4.

Polyethylene is used as the material of the inner tube 4, and polyethylene is used as the material of the outer tube 6. The coil 5 is made of stainless steel wire.

Next, the manufacturing method will be described.

Step 1: A copper wire having the same inner diameter as the inner pipe is coated with a polyethylene synthetic resin to form the inner pipe 4.

Step 2: Next, the stainless steel strip wire is wound from the base end side to 1300 mm (base end portion 11) in a coiled form at a pitch of 0.5 mm while maintaining the winding tension at about 2.5 kg. From 1300 mm to near the tip (tip 12), the winding tension is about 0.5 kg without changing the pitch.
The coil 5 is formed by winding it up to the vicinity of the tip while temporarily maintaining it at the position, temporarily fixing it near the tip, and cutting the strip wire.

Step 3: A platinum wire is wound around the tip portion 9 of the inner tube by about 0.5 mm to form the marker 7.

Step 4: Next, a synthetic resin to be the outer tube 6 is coated on the coil.

Step 5: The copper wire is pulled out, the hub 3 is connected, and the catheter 1 is formed.

In the catheter 1 thus produced, the distal end portion 12 was more flexible than the proximal end portion 11, moreover kink resistance, and torque transmission was excellent.

[0037]

Second Embodiment In step 2 of the first embodiment, 1300
It was prepared in the same manner as in Example 1 except that it was wound at a pitch of 0.7 mm from the mm to the vicinity of the tip.

The flexibility of the distal end portion of the catheter of this example was further enhanced, and it was possible to apply the catheter to a blood vessel having higher flexibility.

[0039]

[Example 3] Example 3 except that in Step 2 of Example 1, winding is performed while maintaining the winding tension at about 1000 mm from the base end portion while maintaining the winding tension at about 3 Kg, and gradually loosening the winding tension from 1000 mm toward the tip end toward the tip end. Created the same as 1.

The catheter of this embodiment has a gradually increasing flexibility toward the distal end, and is excellent in kink resistance.

[0041]

[Example 4] The same as Example 1 except that the inner tube was made of a polyurethane resin, the outer tube was made of a fluororesin, and the inner surface of the inner tube was coated with silicone oil to improve slidability with the guide wire. A catheter of similar construction was formed. The operability with the guide wire has been improved, and it has become possible to apply it to blood vessels with high flexibility.

[0042]

Fifth Embodiment Since the basic structure of this embodiment is the same as that of the first embodiment, it will be described with reference to FIGS. 1 and 2. The same reference numerals are used for the same components even if the materials are different. The catheter comprises a tubular body 2 and a hub 3, and the tubular body 2
Has a total length of 1100 mm, is composed of an inner tube 4, a coil 5, and an outer tube 6, and the inner surface of the inner tube 4 and the outer surface of the outer tube 6 are coated with a hydrophilic polymer 9. The inner tube 4 has an inner diameter of 0.4 mm, a thickness of 0.2 mm, the coil 5 is made of a titanium wire having a diameter of 0.2 mm, and the outer tube 6 has a thickness of 0.2 mm.
mm. A coil-shaped platinum marker 7 having a high X-ray contrast property is embedded in order to easily confirm the position of the tip 9 of the tubular body. A hub 3 is connected to the base end 10,
The inner lumen of the hub 3 communicates with the lumen 8 of the inner tube 4.

Polyurethane resin is used as the material of the inner tube 4, and polyurethane resin is also used as the material of the outer tube 6. Further, the titanium wire is fixed while being buried in the outer surface of the inner tube 4 and the inner surface of the outer tube 6.

Almost the same as the first embodiment, the following steps were performed.

Step 1: A copper wire having the same inner diameter as the inner tube 4 is coated with polyurethane resin to form the inner tube 4.

Step 2: Next, a titanium wire is closely coiled from the base end side up to 900 mm (base end portion 11) at a pitch of 0.3 mm while maintaining the winding tension at 5 Kg. (Tip portion 12), the coil 5 is formed by winding up to the vicinity of the tip 9 while maintaining the winding tension at 1 Kg without changing the pitch, temporarily fixing near the tip and cutting the band wire.

Step 3: Add a platinum wire to the tip of the inner tube 4 to
The marker 7 is formed by winding about 5 mm.

Step 4: Next, a polyurethane resin to be the outer tube 6 is coated on the coil 5. At this time, the coil 5 seems to be buried in the boundary surface between the inner pipe 4 and the outer pipe 6.

Step 5: Subsequently, after removing the copper wire, it is immersed in a solution of a hydrophilic polymer and dried to coat the surface with a hydrophilic resin layer.

Step 6: Connect the hub 3 to form the catheter 1.

In the catheter 1 thus manufactured, the distal end portion 12 is more flexible than the proximal end portion 11, and since the titanium wire is embedded, the rigidity of the proximal end portion 11 is maintained, Operability is improved.

[0052]

The catheter of the present invention comprises a synthetic resin inner tube, a coil provided or embedded outside the inner tube, and a synthetic resin outer tube provided outside the coil. Since the winding tension of the coil is higher on the proximal side than on the distal side, the coil is inserted over the entire length of the catheter, so it is excellent in kink resistance and also in pushability and torque transmission. . Furthermore, since the coil winding tension is weaker on the distal side than on the proximal side, the flexibility on the distal side is higher than that on the proximal side, and it has good followability even when introduced into a bent blood vessel. Has become.

In the catheter of the present invention, the winding tension of the coil is about 2 to 6 kg on the proximal side and about 2 K on the distal side.
Since it is less than g, the rigidity of the base end and the flexibility of the tip can be clearly set.

Further, in the catheter of the present invention, since the coil winding tension between the proximal end side and the distal end side is gradually changed, the coil winding tension is gradually increased from the distal end side to the proximal end side. Since there is no change in the rigidity of the catheter, the kink is less likely to occur.

Since the inner surface of the catheter of the present invention is coated with a hydrophilic substance, the operability of the guide wire is improved.

In the catheter of the present invention, the outer surface of the catheter is coated with a hydrophilic substance, so that it has excellent antithrombotic properties.

In the catheter of the present invention, since the coil is selected from the group consisting of stainless steel, titanium, iron, tungsten and boron, the elongation of the material itself is small and the initial tension can be maintained.

In the catheter of the present invention, the coil on the distal end side has a wider coil pitch as it goes to the distal end, and the coil on the distal end side is annealed to enhance flexibility. In addition, the flexibility of the tip is higher and the followability to the tortuous blood vessel is better.

In the catheter of the present invention, the synthetic resin inner tube is selected from the group consisting of polyurethane, tetrafluorophenylene, nylon elastomer, polyethylene, polyethylene elastomer, polyester, polyester elastomer, and fluororesin. It is possible to provide a catheter that is not crushed by tension and has high kink resistance, improves the processing characteristics of the outer surface, and facilitates coating with a hydrophilic polymer.

In the catheter of the present invention, since the synthetic resin inner tube and the outer tube are made of the same synthetic resin material,
The synthetic resin inner tube and the synthetic resin outer tube are partially compatible with each other, and the coil is embedded in the resin, so that the tension of the coil can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall image of catheters of Examples 1 and 5. FIG.

FIG. 2 is a partial cross-sectional view of catheters of Examples 1 and 5.

[Explanation of symbols]

 1: Catheter 2: Tubular body 3: Hub 3 4: Inner tube 5: Coil 6: Outer tube 7: Platinum marker 8: Inner tube lumen 9: Tip 10: Base end 11: Base end 12: Tip

Claims (10)

[Claims] 1. A synthetic resin inner tube, a coil provided or embedded outside the inner tube, and a synthetic resin outer tube provided outside the coil, wherein the winding tension of the coil is A catheter characterized in that the proximal side is higher than the distal side. 2. The winding tension of the coil is about 2 to 6 on the proximal end side.
The catheter of claim 1, wherein the catheter has a Kg of less than about 2 Kg on the distal side. 3. The catheter according to claim 1, wherein the winding tension of the coil between the proximal end side and the distal end side gradually changes. 4. The catheter according to claim 1, wherein the inner surface of the catheter is coated with a hydrophilic substance. 5. The catheter according to claim 1, wherein the outer surface of the catheter is coated with a hydrophilic substance. 6. The coil comprises stainless steel, titanium, iron,
The catheter according to any one of claims (1) to (5), which is selected from the group consisting of tungsten and boron. 7. The catheter according to claim 1, wherein the coil on the distal end side has a coil pitch which increases as it goes to the distal end. 8. The catheter according to claim 1, wherein the coil on the distal end side is annealed to enhance flexibility. 9. The synthetic resin inner tube and the synthetic resin outer tube are made of polyurethane, tetrafluoroethylene, nylon elastomer, polyethylene, polyethylene elastomer,
The catheter according to any one of claims (1) to (8), which is selected from the group consisting of polyester, polyester elastomer, and fluororesin. 10. The catheter according to claim 1, wherein the inner tube made of synthetic resin and the outer tube are made of the same synthetic resin material.