JP6913664B2 - Balloon catheter - Google Patents

Description

The present invention relates to a balloon catheter that is inserted into a stenosis or the like in a blood vessel to expand the stenosis or the like.

A balloon catheter that is inserted into a stenosis or the like in a blood vessel to expand the stenosis or the like has already been proposed. The balloon catheter mainly consists of a balloon which is an expansion body, an outer shaft joined to the base end of the balloon, and an inner shaft inserted inside the balloon and the outer shaft. Further, the inside of the balloon is generally provided with a metal marker member having radiation impermeableness, and the position of the balloon can be grasped under irradiation.

For example, Patent Document 1 discloses a vasodilator catheter in which a platinum contrast marker (marker member) is attached to a medical tube (inner shaft) including an inner layer, a coil layer which is a reinforcing layer, and an outer layer.

Further, for example, in Patent Document 2, an X-ray opaque marker is fitted in a concave groove arranged on an outer peripheral surface of an inner tube (inner shaft) inside a balloon, and a heat-shrinkable tube is coated on the balloon expansion. The catheter is disclosed. Further, a balloon expansion catheter in which an X-ray opaque marker is arranged without providing a concave groove on the outer peripheral surface of an inner tube (inner shaft) and a heat-shrinkable tube is coated on the X-ray opaque marker is also disclosed.

Japanese Patent No. 3659664 Japanese Patent No. 3219968

However, in the vasodilator catheter disclosed in Patent Document 1, a marker member is attached to the outer peripheral surface of the inner shaft, and the marker member is exposed on the inner peripheral surface side of the balloon. The ends of the member may damage the balloon. In addition, there is a problem that a difference in rigidity occurs between the flexible inner shaft and the highly rigid marker member, and stress may be excessively concentrated at the mounting position of the marker member, causing the inner shaft to buckle. be.

Further, the balloon expansion catheter disclosed in Patent Document 2 has a problem that the manufacturing process is complicated because processing processing such as polishing and etching for providing a concave groove is required. Further, there is also a problem that the strength of the portion provided with the concave groove tends to decrease due to the cross-sectional defect. Further, in the configuration in which the X-ray opaque marker is arranged on the outer peripheral surface of the inner tube (inner shaft) and covered with the heat-shrinkable tube, the outer diameter of the balloon portion becomes large, so that it is difficult to reduce the diameter of the balloon catheter. .. Further, if the marker member is made of a highly rigid metal, it is difficult for the marker member itself to be deformed following the curvature of a blood vessel or the like, and there is also a problem that the marker member is easily caught at a position where the marker member is arranged.

Therefore, according to the present invention, there is no risk of damaging the balloon, the diameter of the portion where the marker member is arranged can be reduced, and even when the balloon is inserted into a curved blood vessel, the balloon is caught at the position where the marker member is arranged. It is an object of the present invention to provide a balloon catheter that can be prevented.

The present invention is a balloon catheter including a balloon and an inner shaft joined to the balloon. The inner shaft is arranged on an inner layer and an outer periphery of the inner layer, and a loosely wound portion in which a wire is loosely wound. A coil body having a Is arranged at a position facing the gap formed between the strands of the loosely wound portion.

In such a configuration, when the balloon catheter is inserted into a curved blood vessel, at least one of the tip end portion and the proximal end portion of the marker member enters the gap formed between the strands of the coil body. be able to. Therefore, the stress concentration generated at the portion where the marker member is arranged is relaxed, and it is possible to prevent the inner shaft from buckling. Further, it is possible to prevent the end portion of the marker member from protruding toward the inner peripheral surface side of the balloon. Further, since the marker member is covered with the outer layer without using a separate member, the manufacturing process is not complicated. Further, there is no possibility that the marker member will damage the balloon. Further, since the outer layer covering the coil body also has a function of covering the marker member in this way, it is possible to prevent the outer diameter of the inner shaft from becoming excessively large in the balloon.

For example, when the tip of the marker member is arranged at a position facing the gap, at least a part of the tip may be arranged at a position facing the gap. Similarly, for example, when the base end portion of the marker member is arranged at a position facing the gap portion, at least a part of the base end portion may be arranged at a position facing the gap portion.

Further, it is desirable that at least one of the tip end portion and the base end portion of the marker member is curved inward.

In such a configuration, since at least one of the tip end portion and the base end portion has a continuous tapered shape without a step, it is possible to prevent balloon rupture (rupture or breakage) by the marker member. Further, even when the balloon catheter is curved and an external force is applied to the marker member, the edge of the marker member that has entered the gap is in contact with the wire of the coil body to suppress the movement of the marker member. can do.

In the balloon catheter of the present invention, there is no risk of damaging the balloon, the diameter of the portion where the marker member is arranged can be reduced, and in addition, at the position where the marker member is arranged even when inserted into a curved blood vessel. It is possible to prevent it from being caught.

FIG. 5 is a partial cross-sectional plan view of the balloon catheter according to the first embodiment. It is a partially enlarged sectional view of the balloon catheter which concerns on Example 1. FIG. It is a partially enlarged sectional view which shows the state at the time of bending of the balloon catheter which concerns on Example 1. FIG. It is a partially enlarged sectional view of the balloon catheter which concerns on Example 2. FIG. It is a partially enlarged sectional view of the balloon catheter which concerns on Example 3. FIG. It is explanatory drawing explaining the marker member of the balloon catheter which concerns on Example 4. FIG.

Hereinafter, examples in which the balloon catheter of the present invention is embodied will be described in detail. However, the present invention is not limited to the examples shown below, and the design can be changed as appropriate. In FIGS. 1 to 5, the left side is the distal end side (distal side) inserted into the body, and the right side is the proximal end side (proximal side) operated by a technician such as a doctor. Further, those smaller than other parts such as the marker member 70 arranged inside the balloon 20 are shown with a slight exaggeration in relation to the dimensions of the other members in order to facilitate understanding.

[Example 1]
For example, the balloon catheter 10 used for treating a stenosis in a blood vessel of the heart includes a balloon 20, an outer shaft 30, a connector 40, an inner shaft 50, and a tip 60, as shown in FIG. ing.

The balloon 20 has a function of expanding a narrowed portion and is made of a resin member. The tip mounting portion 22 is provided on the tip side, and the base end mounting portion 23 is provided on the base end side. The tip mounting portion 22 is joined to the tip of the inner shaft 50 via a tip 60, and the base end mounting portion 23 is joined to the tip of the outer shaft 30.

The outer shaft 30 has a function of supplying a fluid, and is composed of a tubular member constituting an expansion lumen 36 for supplying the fluid. Further, the outer shaft 30 has a tip outer shaft portion 31, a guide wire port portion 33, an intermediate outer shaft portion 35, and a base end outer shaft portion 37 in this order from the tip side. The guide wire port portion 33 is a portion where the tip outer shaft portion 31, the intermediate outer shaft portion 35, and the inner shaft 50 are joined.

More specifically, the inner shaft 50 is inserted into the tip outer shaft portion 31, and the expansion lumen 36 is formed between the tip outer shaft portion 31 and the inner shaft 50. .. Further, the base end outer shaft portion 37 is made of a metal tubular member called a so-called hypotube. Then, the tip of the base end outer shaft portion 37 is inserted into the base end of the intermediate outer shaft portion 35 and joined. Further, a connector 40 is attached to the base end of the base end outer shaft portion 37. Then, when a liquid such as a contrast medium or physiological saline for expanding the balloon 20 is supplied from an indeflator (not shown) attached to the connector 40, the liquid flows into the balloon 20 through the expansion lumen 36. Then, the balloon 20 expands.

The tip outer shaft portion 31 and the intermediate outer shaft portion 35 are preferably made of a tube made of a resin such as polyamide, polyamide elastomer, polyolefin, polyester, or polyester elastomer. Further, the base end outer shaft portion 37 is preferably made of a superelastic alloy such as stainless steel (SUS304) or Ni—Ti alloy.

Further, a core wire 90 is attached to the inner peripheral surface of the tip of the base end outer shaft portion 37. The core wire 90 has a circular cross section and is made of a tapered metal wire whose diameter is reduced toward the tip. The core wire 90 passes through the intermediate outer shaft portion 35 and the guide wire port portion 33, and is formed to extend to the tip outer shaft portion 31. Further, the core wire 90 has a pressing portion 92 near the rear end of the guide wire port portion 33. As a result, when a pushing force or a rotational force acts on the core wire 90, the pressing portion 92 abuts on the guide wire port portion 33, so that the pushing force or the rotational force is transmitted to the tip outer shaft portion 31 and the inner shaft 50. Will be done. Alternatively, instead of providing the pressing portion 92, the core wire 90 is joined to the guide wire port portion 33, so that when a pushing force or a rotational force acts on the core wire 90, the core wire 90 is pushed through the guide wire port portion 33. A force or a rotational force may be transmitted to the tip outer shaft portion 31 and the inner shaft 50. The core wire 90 is preferably made of a superelastic alloy such as stainless steel (SUS304) or Ni—Ti alloy.

Further, at the base end of the inner shaft 50, a base end side guide wire port 55 is formed by being joined to the guide wire port portion 33 of the outer shaft 30. Further, a tip side guide wire port 69 is formed on the tip 60 arranged at the tip of the inner shaft 50.

Further, as shown in FIG. 2, the inner shaft 50 has a tubular inner layer 51 forming a guide wire lumen 511 for inserting a guide wire (not shown) inside.

Further, a coil body 52 covering the inner layer 51 is arranged on the outer periphery of the inner layer 51. The coil body 52 has a loosely wound portion 522 in which a strand 521 having a rectangular cross section is loosely wound, and a gap is formed between the strands 521.

Further, two cylindrical marker members 70 are arranged on the distal side and the proximal side on the outer circumference of the loosely wound portion 522 of the coil body 52 inside the balloon 20. Further, an outer layer 53 that covers the coil body 52 and the marker member 70 is formed.

The inner layer 51 and the outer layer 53 are preferably made of a resin such as polyethylene, polyurethane, polyamide, polyamide elastomer, polyolefin, polyester, or polyester elastomer. Further, the coil body 52 is preferably made of a superelastic alloy such as stainless steel (SUS304) or Ni—Ti alloy. Further, the marker member 70 is preferably made of a radiation-impermeable metal material such as platinum or tungsten.

Further, in the region between the strands 521 of the coil body 52 where the marker member 70 is not arranged, the outer layer 53 is filled in the gap between the strands 521. On the other hand, in the region where the marker member 70 is arranged, a gap portion 54 is formed in which the outer layer 53 is not filled in the gap. The tip end portion 701 and the base end portion 702 of the marker member 70 are arranged at positions facing the gap portion 54.

In the balloon catheter 10 having the above configuration, when the balloon catheter 10 is inserted into the curved blood vessel, the inner shaft 50 is curved along the blood vessel as shown in FIG. At this time, inside the curved inner shaft 50, a part of the tip portion 701 and a part of the base end portion 702 of the marker member 70 can enter the gap portion 54 in the coil body 52. Therefore, the stress concentration generated at the portion where the marker member 70 is arranged is relaxed, and it is possible to prevent the inner shaft 50 from buckling. Further, it is possible to prevent the tip end portion 701 and the base end portion 702 of the marker member 70 from protruding toward the inner peripheral surface side of the balloon 20. Further, since the marker member 70 is covered with the outer layer 53 without using a separate member, the manufacturing process is not complicated and there is no risk of damaging the inner peripheral surface of the balloon 20. Further, since the outer layer 53 also has a function of covering the marker member 70 and the coil body 52, it is possible to prevent the outer diameter of the inner shaft 50 from becoming large in the balloon 20, and the diameter of the inner shaft 50 is reduced. Is possible.

[Example 2]
Hereinafter, Example 2 will be described with reference to FIG. The parts common to the first embodiment will be omitted from the description, and the same reference numerals will be given in the drawings.

It is desirable that both the tip end portion 701 and the base end portion 702 of the marker member 70 are arranged at positions facing the gap portion 54, but even in the configuration according to the second embodiment, the inner shaft 50 buckles. It is possible to prevent it from being stored.

Specifically, as shown in FIG. 4A, only the base end portion 702 of the marker member 70 may be arranged at a position facing the gap portion 54. At this time, the outer layer 53 is filled in the gap between the strands 521 facing the tip end portion 701 of the marker member 70.

Further, as shown in FIG. 4B, only the tip portion 701 of the marker member 70 may be arranged at a position facing the gap portion 54. At this time, the outer layer 53 is filled in the gap between the strands 521 facing the base end portion 702 of the marker member 70.

[Example 3]
Hereinafter, Example 3 will be described with reference to FIG. The parts common to the first and second embodiments will be omitted, and the same reference numerals will be given in the drawings.

As shown in FIG. 5, it is preferable that the tip end portion 711 and the base end portion 712 of the marker member 71 are curved inward so as to project toward the gap portion 54. With such a configuration, the tip end portion 711 and the base end portion 712 have a smooth continuous tapered shape without a step. Therefore, there is no possibility that the inner peripheral surface of the balloon 20 will be damaged by the end portion of the marker member 71, and rupture (rupture or breakage) of the balloon 20 by the marker member 71 can be prevented. Further, even when the balloon catheter 10 is curved and an external force is applied to the marker member 71, the end portion of the marker member 71 that has entered the gap portion 54 comes into contact with the wire 521 of the coil body 52. The movement of the marker member 71 can be suppressed.

It is desirable that the tip portion 711 and the base end portion 712 of the marker member 71 are curved inward, but at least one of the tip portion 711 and the base end portion 712 may be curved inward.

[Example 4]
Hereinafter, Example 4 will be described with reference to FIG. The parts common to the above Examples 1 to 3 will be omitted from the description, and the same reference numerals will be given in the drawings.

The marker member 72 can be formed by bending a metal plate A having a parallelogram in a plan view as shown in FIG. 6A. Then, as shown in FIG. 6B, substantially the entire tip end portion 721 and the base end portion 722 of the marker member 72 may be arranged at positions facing the gap portion 54. Further, the tip end portion 721 and the base end portion 722 of the marker member 72 may be curved inward.

In Examples 1 to 4, the number of marker members 70 to 72 arranged in the balloon 20 may be singular or plural. Further, the cross-sectional shape of the wire 521 of the coil body 52 is not limited to the rectangular cross-sectional shape, and may be another shape such as a circular cross-sectional shape.

10 Balloon catheter 20 Balloon 30 Outer shaft 50 Inner shaft 51 Inner layer 52 Coil body 53 Outer layer 54 Voids 70, 71, 72 Marker member 521 Wire 522 Sparse winding 701,711,721 Tip tip 702,712,722 Base end

Claims (2)

With a balloon
The inner shaft joined to the balloon and
In a balloon catheter equipped with
The inner shaft is inside the balloon.
Inner layer and
A coil body arranged on the outer periphery of the inner layer and having a sparsely wound portion in which strands are sparsely wound, and a coil body.
A marker member arranged on the outer circumference of the coil body and
An outer layer that covers the coil body and the marker member,
Have,
In the region where the outer layer is filled in the gap between the strands and the marker member is arranged, a gap portion in which the outer layer is not filled in the gap is formed between the strands of the loosely wound portion. And
A balloon catheter characterized in that at least one of a tip end portion and a proximal end portion of the marker member is arranged at a position facing the gap portion. The balloon catheter according to claim 1, wherein at least one of the tip end portion and the proximal end portion of the marker member is curved inward.

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