JP2012217461A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter sufficiently transmitting a turn imparted from a near side of the balloon catheter to a remote side of the balloon catheter.SOLUTION: This balloon catheter 10 includes a plurality of rotation transmission members 80 disposed between an outer shaft 30 and an inner shaft 50, positioning the inner shaft 50 coaxially with the outer shaft 30, and connecting the outer shaft 50 and the inner shaft 30.

Description

  The present invention relates to a balloon catheter used for dilating a stenosis in a body cavity such as a blood vessel.

  Conventionally, a balloon catheter is used to dilate a stenosis portion in a body cavity such as a blood vessel. The balloon catheter is mainly composed of a balloon as an expansion body, an outer shaft, and an inner shaft arranged inside the balloon. The inner shaft is for inserting a guide wire, and the outer shaft is for circulating a liquid such as a contrast medium or physiological saline for expanding the balloon through a lumen provided between the inner shaft and the inner shaft. Is.

  Since such a balloon catheter is inserted into a blood vessel or the like and positioned at a desired position, a force such as a doctor who pushes the catheter in the axial direction from the proximal side to the distal side of the catheter, that is, a so-called pushing force is generated. Communicated. The balloon catheter is required to have a high performance for transmitting the pushing force from the proximal side to the distal side, that is, a high pushing property.

  Conventionally, in order to improve the push-in characteristics and change the rigidity of the balloon catheter in the axial direction, there is one having a core wire in the outer shaft (for example, see Patent Document 1 below). Some balloon catheters having such a core wire have a core wire having a distal end portion fixed to a part of the catheter in order to further improve the push-in characteristics (see, for example, Patent Documents 2 to 5 below).

JP 2002-291899 A JP 2004-160101 A Special table 2003-517901 gazette Japanese National Patent Publication No. 8-500505 Japanese National Patent Publication No. 9-503411

  Recently, in addition to improving the push-in characteristics, when the balloon catheter passes through a bendable blood vessel, the tip of the balloon catheter is caught at the inner wall of the blood vessel, making it difficult to pass, etc. There is a request to rotate. That is, there is a demand for a rotational follow-up property in which the distal end side follows and rotates when the proximal side of the balloon catheter is rotated by a certain angle.

  The conventional balloon catheter as described above is considered to have a certain effect in order to improve the push-in characteristic, but it is not sufficient for the balloon catheter to have a rotational followability. Since the balloon is attached to the distal end of the outer shaft of the balloon catheter, even if the outer shaft is rotated on the hand side, the rotational force is blocked by the balloon and is the distal end of the balloon catheter. This is because it is difficult to be transmitted to the tip of the inner shaft.

  This invention is made | formed in view of such a situation, and it aims at providing the balloon catheter which can fully transmit the rotation given from the proximal side of a balloon catheter to the distal side of a balloon catheter. .

  In the present invention, the above problems are solved by the means listed below.

<1> A balloon, a tubular outer shaft to which a mounting portion on the rear end side of the balloon is joined, and a portion that extends from the outer shaft and is inserted into the outer shaft. An inner shaft to which a mounting portion is joined, and a plurality of members that are disposed between the outer shaft and the inner shaft, position the inner shaft coaxially with the outer shaft, and connect the outer shaft and the inner shaft. A rotation transmission member.

<2> The balloon catheter according to aspect 1, wherein the plurality of rotation transmission members include at least three rotation transmission members arranged at equal intervals in the circumferential direction of the inner shaft.

<3> The balloon catheter according to aspect 1 or 2, wherein the rotation transmission member has a hole penetrating in the axial direction.

<1> The balloon catheter of the present invention can rotate the tip of the balloon catheter by transmitting the rotational force applied by the operator from the outer shaft to the inner shaft by the rotation transmitting member. At this time, since the inner shaft is coaxially connected in the outer shaft, the rotational force can be effectively transmitted from the outer shaft to the inner shaft.

  Accordingly, when the balloon catheter passes through a bendable blood vessel or the like, the operator can turn the tip of the balloon catheter by turning the outer shaft, so the balloon catheter is attached to the bendable blood vessel or the like. It can pass well.

<2> In the aspect 2 of the present invention, the plurality of rotation transmission members are composed of at least three rotation transmission members arranged at equal intervals in the circumferential direction of the inner shaft. That is, at least three rotation transmission members are evenly arranged in the expansion lumen formed between the outer shaft and the inner shaft. Such an arrangement is effective in stably arranging the outer shaft and the inner shaft coaxially, and can effectively transmit the rotational force of the outer shaft to the inner shaft.

<3> In the aspect 3 of the present invention, the rotation transmission member has a hole penetrating in the axial direction. By adopting such a configuration, it is possible to prevent the expansion lumen from becoming narrow even if a plurality of rotation transmission members exist between the outer shaft and the inner shaft. That is, the opening area of the expansion lumen can be secured by the through-hole. For this reason, even if the rotation transmitting member is arranged, it is possible to prevent the time for expanding and contracting the balloon from becoming long.

FIG. 1 is an overall view of a balloon catheter according to the present embodiment. FIG. 2 is an enlarged view of the distal end portion of the balloon catheter of FIG. 3 is a cross-sectional view as seen from the direction of III-III in FIG. FIG. 4 is a diagram showing another embodiment. FIG. 5 is a diagram showing still another embodiment.

  The balloon catheter of the present embodiment will be described with reference to FIGS. 1 and 2, the left side in the figure is the distal end side (distal side) to be inserted into the body, and the right side is the rear end side (proximal side, proximal end side) operated by an operator such as a doctor.

The balloon catheter 10 is used, for example, for treating a blockage or stenosis of a heart blood vessel, and has a total length of about 1500 mm.
The balloon catheter 10 mainly includes a balloon 20, an outer shaft 30, an inner shaft 50, a connector 60, and a rotation transmission member 80.

  The balloon 20 is a resin member, and has an expansion part 21 for expanding the balloon 20 in the center in the axial direction, a front end attachment part 22 on the front end side, and a rear end attachment part 23 on the rear end side.

The tip attachment portion 22 is fixed to the tip portion (including the tip 59) of the inner shaft 50.
The rear end mounting portion 23 is fixed to the outer peripheral surface of the front end portion of the outer shaft 30.

  The outer shaft 30 is a tubular member that forms an expansion lumen 36 for supplying a fluid for expanding the balloon 20. The outer shaft 30 includes a distal end outer shaft portion 31 located on the distal side and a rear end outer shaft portion 37 located on the rear end side. The distal end outer shaft portion 31 is a resin tube. For example, polyamide, polyamide elastomer, polyolefin, polyester, polyester elastomer, or the like is used as the resin constituting the distal end outer shaft portion 31.

  A rear end attachment portion 23 of the balloon 20 is fixed to the outer periphery of the distal end portion of the distal outer shaft portion 31. In the case of the present embodiment, the rear end mounting portion 23 is fixed to the outer peripheral surface of the front end portion of the front outer shaft portion 31, but may be fixed to the inner peripheral surface of the front end portion of the front outer shaft portion 31. .

  Further, the distal outer shaft portion 31 houses the inner shaft 50. The rear end of the inner shaft 50 is attached to the side surface of the front outer shaft portion 31, and the rear end side guide wire port 54 is formed on this side surface. A space between the distal outer shaft portion 31 and the inner shaft 50 is a distal expansion lumen 36 a that constitutes the distal end portion of the expansion lumen 36.

Three rotation transmitting members 80, which will be described later, are disposed at the distal end portion of the expansion lumen 36a.
A core wire 90 described later is inserted into the expansion lumen 36a.

  In the present embodiment, the outer diameter of the distal end outer shaft portion 31 is set to about 0.80 mm to about 0.95 mm, and is about 0.84 mm. In the present embodiment, the inner diameter of the distal outer shaft portion 31 is set to about 0.70 mm to about 0.85 mm, and is about 0.73 mm.

  The rear end outer shaft portion 37 is a metal tubular member called a so-called hypotube. The front end portion of the rear end outer shaft portion 37 is inserted and fixed to the rear end portion of the front end outer shaft portion 31. The rear end expansion lumen 36b formed inside the rear end outer shaft portion 37 constitutes the expansion lumen 36 together with the above-described front end expansion lumen 36a.

  A connector 60 is attached to the rear end of the rear end outer shaft portion 37. When 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 60, the liquid expands the balloon 20 through the expansion lumen 36. ing.

  In the case of the present embodiment, the outer diameter of the rear end outer shaft portion 37 is set in the range of about 0.60 mm to about 0.65 mm in the case of the present embodiment, and is about 0.64 mm. In this embodiment, the inner diameter is about 0.48 mm. The material of the rear end outer shaft portion 37 is not particularly limited, but in the case of the present embodiment, stainless steel is used. As a material other than this, a superelastic alloy such as a Ni-Ti alloy is used.

  A core wire 90 is attached to the inner peripheral surface of the distal end portion of the rear end outer shaft portion 37. The rear end of the core wire 90 is fixed to the inner peripheral surface of the rear end outer shaft portion 37 by brazing, welding by laser, or the like.

  The core wire 90 is inserted into the expansion lumen 36 a in the distal end outer shaft portion 31. The core wire 90 is a metal wire having a circular cross-sectional shape. The distal end of the core wire 90 extends to the distal end side beyond the rear end side guide wire port 54, but does not reach the rear end of the rotation transmitting member 80 described later. The material of the core wire 90 is not particularly limited, but in the present embodiment, stainless steel (SUS304) is used. As other materials, a super elastic alloy such as a Ni-Ti alloy, a piano wire, or the like is used.

  The core wire 90 is reduced in diameter toward the distal end in order to give a change in rigidity so that the balloon catheter 10 becomes flexible toward the distal end. In the present embodiment, the core wire 90 has a diameter that decreases from about 0.45 mm to about 0.10 mm in the distal direction.

  The inner shaft 50 is housed in the distal end outer shaft portion 31. The inner shaft 50 is a tubular member formed of the same resin as the distal outer shaft portion 31 and has a guide wire lumen 51 for inserting a guide wire therein.

  In the case of the present embodiment, the outer diameter of the inner shaft 50 is set in the range of about 0.50 mm to about 0.60 mm in the case of the present embodiment, and is about 0.53 mm. In the present embodiment, the inner diameter is set to a range of about 0.36 mm to about 0.45 mm, and is about 0.41 mm.

  A rear end side guide wire port 54 is formed by welding the rear end of the inner shaft 50 to the side surface of the front outer shaft portion 31.

The distal end portion of the inner shaft 50 has an extending portion 52 that extends from the distal end of the distal outer shaft portion 31. The extending part 52 has a tip 59 at the tip.
The chip 59 is a member having a tapered outer shape whose outer diameter gradually decreases toward the tip, and is formed of a flexible resin. The tip 59 is a cylindrical member that forms the distal end portion of the guide wire lumen 51, and has a distal end side guide wire port 53 at the distal end.

  The distal end mounting portion 22 of the balloon 20 is fixed to the distal end portion (including the tip 59) of the extending portion 52 of the inner shaft 50.

  A pair of radiopaque markers 70 spaced apart from each other by a predetermined distance are attached to a portion of the extended portion 52 of the inner shaft 50 positioned inside the expanded portion 21 of the balloon 20.

  A plurality of rotation transmitting members 80 are arranged at equal intervals in the circumferential direction between the distal outer shaft portion 31 and the inner shaft 50. The rotation transmitting member 80 is a cylindrical member having a circular cross section and a constant diameter. The number and material of the rotation transmitting member 80 are not particularly limited, but in the case of the present embodiment, three wire wires having the same shape are used. Although it does not specifically limit as a metal material, In the case of this Embodiment, stainless steel (SUS304) is used. As other materials, a super elastic alloy such as a Ni-Ti alloy, a piano wire, or the like is used. In addition to the metal, a resin wire can be used.

  The rotation transmitting member 80 is arranged so that the tip is located near the tip of the tip outer shaft portion 31. That is, the distal end of the rotation transmitting member 80 is disposed so as to overlap a portion of the distal end outer shaft portion 31 to which the rear end attaching portion 23 of the balloon 20 is fixed. By arranging the rotation transmitting member 80 as far as possible on the distal end side of the outer shaft 30 in this way, the rotational force transmitted by the outer shaft 30 can be transmitted to the inner shaft 50 on the distal end side of the balloon catheter 10. Rotational force transmission can be improved.

  The rotation transmitting member 80 is interposed so as to connect the inner peripheral surface of the distal end outer shaft portion 31 and the outer peripheral surface of the inner shaft 50, and is fixed by an adhesive. The three rotation transmission members 80 have the same diameter, and are set so that the inner shaft 50 is positioned substantially coaxially with respect to the distal end outer shaft portion 31. That is, as shown in FIGS. 2 and 3, the central axis of the inner shaft 50 is arranged so as to coincide with the central axis A of the distal end outer shaft portion 31. For this reason, the diameter of the rotation transmission member 80 is determined in consideration of the inner diameter of the distal outer shaft portion 31 and the outer diameter of the inner shaft 50. In the case of the present embodiment, the diameter of the rotation transmitting member 80 is set in the range of about 0.03 mm to about 0.13 mm, and is about 0.10 mm.

  The above-described rotation transmission member 80 is fixed by an adhesive between the inner peripheral surface of the distal end outer shaft portion 31 and the outer peripheral surface of the inner shaft 50. However, the rotation transmission member 80 is heated using induction heating or the like. By doing so, it can also be made to adhere between the front-end | tip outer shaft part 31 and the inner shaft 50. FIG.

  The three rotation transmitting members 80 are arranged at equal intervals in the circumferential direction so as to divide the distal end expansion lumen 36a formed between the distal outer shaft portion 31 and the inner shaft 50 substantially evenly. That is, the rotation transmitting members 80 are arranged at equal angle θ (= 120 °) intervals around the central axis A.

The length of the rotation transmitting member 80 is not particularly limited. However, in order to effectively transmit the rotational force from the outer end outer shaft portion 31 to the inner shaft 50, the inner diameter of the outer end outer shaft portion 31 is increased by line contact. Since it is preferable that the peripheral surface and the outer peripheral surface of the inner shaft 50 are joined, it has a predetermined length in the axial direction.
In the case of the present embodiment, the axial length of the rotation transmitting member 80 is set in a range of about 3.0 mm to about 20.0 mm, and is about 10.0 mm. In order to transmit the rotational force as close to the tip of the inner shaft 50 as possible,
The rotation transmitting member 80 is disposed on the front end side from the rear end side guide wire port 54.

  In the above-described embodiment, the lengths of the plurality of rotation transmission members 80 are the same, but the lengths of the plurality of rotation transmission members 80 may be different.

  With such a configuration, when the distal outer shaft portion 31 is rotated about the axis by the rotation of the rear outer shaft portion 37, the three rotation transmission members 80 are arranged at the distal end portion of the outer outer shaft portion 31. Rotational force is transmitted to the inner shaft 50, and the inner shaft 50 is rotated coaxially with the distal end outer shaft portion 31. In other words, the plurality of rotation transmitting members 80 support the inner shaft 50 and the distal outer shaft portion 31 coaxially so that the rotational force of the distal outer shaft portion 31 is effectively transmitted to the inner shaft 50. The rotation of the inner shaft 50 is sequentially transmitted from the extending portion 52 to the tip 59, so that the tip of the balloon catheter 10 is rotated. Therefore, the rotational force applied to the outer shaft 30 from the hand side rotates the tip 59 without being hindered by the balloon 20.

  The rotation includes a case where the outer shaft 30 or the like is displaced by a predetermined angle of less than about 360 ° around the axis. Therefore, the outer shaft 30 or the like does not necessarily need to rotate more than one rotation.

  Based on the above configuration, a case will be described in which the balloon catheter 10 of the present embodiment is used for a procedure for expanding a stenosis in a coronary artery of the heart.

  A guide wire (not shown) is inserted in advance into the coronary artery of the heart where there is a stenosis that is the target of treatment, and the balloon catheter 10 is inserted into the body along this guide wire. The guide wire is inserted from the distal end side guide wire port 53 of the tip 59 of the balloon catheter 10, passes through the guide wire lumen 51 in the inner shaft 50, and extends from the rear end side guide wire port 54.

  When the balloon catheter 10 is advanced in the blood vessel along the guide wire, an operator such as a doctor pushes the balloon catheter 10 in the axial direction from the proximal side, and this pushing force is a rear end outer shaft portion 37 which is a metal tube. Is transmitted to the distal end outer shaft portion 31 from the distal side.

  At the same time, the pushing force is transmitted from the rear end outer shaft portion 37 to the core wire 90 attached to the rear end outer shaft portion 37. Thereby, the transmission property of pushing force can be improved.

  When the balloon catheter 10 passes through a bent blood vessel or the like, the tip of the balloon catheter 10 such as the tip 59 may be caught on the inner wall of the blood vessel and the passage may be inhibited. In such a case, when the technician rotates the rear end outer shaft portion 37, the front end outer shaft portion 31 joined thereto rotates. The rotation of the distal end outer shaft portion 31 is transmitted to the inner shaft 50 by the rotation transmitting member 80 and is sequentially transmitted from the extended portion 52 of the inner shaft 50 to the tip 59. At this time, since the inner shaft 50 is coaxially connected in the distal end outer shaft portion 31, the rotational force can be effectively transmitted from the outer shaft 30 to the inner shaft 50. Accordingly, since the tip 59 rotates, even if the tip portion of the balloon catheter 10 such as the tip 59 is caught by the inner wall of the blood vessel and the movement of the balloon catheter 10 is inhibited, this situation can be solved. Therefore, the balloon catheter 10 can be satisfactorily passed through a bent blood vessel or the like.

  Under the fluoroscopy, the operator positions the balloon 20 at the stenosis, which is the target site, using the marker 70, and then expands liquid such as a contrast medium or physiological saline from an indeflator (not shown) connected to the connector 60. Is supplied. At this time, the expansion liquid flows into the expansion lumen 36 of the outer shaft 30. Then, the expansion liquid flows out from the distal end of the distal end outer shaft portion 31 of the outer shaft 30 to expand the balloon 20.

When the procedure for expanding the stenosis with the balloon 20 is completed, the operator discharges the expansion liquid from the balloon 20 by the inflator. That is, the expansion liquid flows out from the inside of the balloon 20 and is discharged from the front end expansion lumen 36a of the front end outer shaft portion 31 and the rear end expansion lumen 36b of the rear end outer shaft portion 37 to the inflator.
Thereafter, the balloon catheter 10 is pulled out of the body, and the procedure is completed.

  As described above, the balloon catheter 10 of the present embodiment can transmit the rotational force applied by the operator from the outer shaft 30 to the inner shaft 50 by the rotation transmission member 80, and the tip of the balloon catheter 10 can be transmitted. The tip 59 can be rotated. At this time, since the inner shaft 50 is coaxially connected in the distal end outer shaft portion 31, the rotational force can be effectively transmitted from the outer shaft 30 to the inner shaft 50.

  Therefore, when the balloon catheter 10 passes through a bent blood vessel or the like, the operator can turn the distal end of the balloon catheter 10 by turning the rear end outer shaft portion 37. Can be satisfactorily passed through bent blood vessels and the like.

  In the embodiment described above, the three rotation transmission members 80 are spaced equally in the circumferential direction so as to divide the distal end expansion lumen 36a formed between the distal outer shaft portion 31 and the inner shaft 50 substantially evenly. Is arranged in. That is, the rotation transmission members 80 are arranged at intervals of 120 °. Such an arrangement is effective in stably arranging the distal outer shaft portion 31 and the inner shaft 50 coaxially, and can effectively transmit the rotational force of the outer shaft 30 to the inner shaft 50. it can. However, the number of rotation transmitting members 80 is not limited to three. Further, the plurality of rotation transmitting members are not necessarily arranged at equal intervals in the circumferential direction of the distal extension lumen 36a as described above, and various modes can be adopted as shown in FIG. That is, in order to arrange the inner shaft 50 substantially concentrically with respect to the distal end outer shaft portion 31, the rotation transmission members are symmetrically arranged like the rotation transmission members 180 and 280 shown in FIGS. 4 (a) and 4 (b). It is preferable to arrange. However, if the inner shaft 50 is stably disposed substantially coaxially in the outer shaft 30, a plurality of rotation transmission members may be asymmetrical as in the rotation transmission member 380 shown in FIG. You may arrange | position with the non-uniform space | interval with respect to the circumferential direction of 36a.

  In the embodiment described above, the three rotation transmission members 80 are made of a metal columnar member, but are composed of a rotation transmission member 480 made of a hollow cylindrical member as shown in FIG. May be. The rotation transmitting member 480 has a through hole 480a formed in the axial direction. For this reason, since the opening area of the expansion lumen can be enlarged by the amount corresponding to the through hole 480a, it is possible to prevent the expansion lumen 36 from being narrowed by the rotation transmission member 480. Therefore, even if the rotation transmitting member is arranged, it is possible to prevent the expansion lumen from being narrowed and the time for balloon expansion and contraction from being increased.

  In the embodiment described above, the cross-sectional shape of the rotation transmission member 80 is circular. However, the cross-sectional shape of the rotation transmission member 80 is interposed between the outer shaft 30 and the inner shaft 50 and the rotational force of the outer shaft 30 is increased. There is no particular limitation as long as it can be transmitted to the inner shaft 50. For example, it is possible to adopt a cross-sectional shape such as a square or an oval.

In the above-described embodiment, a so-called quick exchange type configuration in which the guide wire lumen 51 is shortened by connecting the inner shaft 50 to the side surface of the distal end side outer shaft 31 is employed. The quick exchange type balloon catheter has an inner shaft that exists only in the middle of the outer shaft.
The rotational force applied from the proximal side is not easily transmitted to the tip of the balloon catheter. For this reason, it is effective to provide the rotation transmission member of the present embodiment to improve the transmission performance of the rotational force. However, it is also possible to adopt a configuration in which a rotation transmission member is provided on a so-called over-the-wire type balloon catheter in which the inner shaft is disposed up to the rear end of the balloon catheter.

  In the embodiment described above, the balloon catheter 10 is used for treatment of the blood vessels of the heart, but can be used for various procedures such as a procedure for expanding the blood vessels of the lower limbs and the shunt for dialysis.

10 balloon catheter 20 balloon 22 distal end attachment portion 23 rear end attachment portion 30 outer shaft 31 distal end outer shaft portion 36 expansion lumen 37 rear end outer shaft portion 50 inner shaft 80 rotation transmission member 480a through hole

Claims (3)

With balloons,
A tubular outer shaft to which a mounting portion on the rear end side of the balloon is joined;
An inner shaft that is inserted into the outer shaft, and an attachment portion on the tip side of the balloon is joined to a portion extending from the outer shaft;
A plurality of rotation transmitting members are disposed between the outer shaft and the inner shaft, position the inner shaft coaxially with the outer shaft, and connect the outer shaft and the inner shaft. A balloon catheter.   2. The balloon catheter according to claim 1, wherein the plurality of rotation transmission members include at least three rotation transmission members arranged at equal intervals in a circumferential direction of the inner shaft.   The balloon catheter according to claim 1, wherein the rotation transmission member has a hole penetrating in the axial direction.

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