JP2013106798A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter that has excellent operability.SOLUTION: The balloon catheter 10 includes: a distal shaft 21 having an elastically expandable balloon 11 provided on the distal end side and whose internal space is made to communicate with an internal space of the balloon 11; an intermediate shaft 22 connected to the distal shaft 21; a proximal shaft 23 connected to the intermediate shaft 22; a guide wire tube 14 provided in the internal space of the distal shaft 21; a fixing tube 17 provided on the outer wall of the guide wire tube 14; and a wire 16 whose distal end side is inserted into the fixing tube 17, whose proximal end side is fixed to the proximal shaft 23, and which is inserted into an internal space of the intermediate shaft 22.

Description

  The present invention relates to a balloon catheter used for a treatment for dilating a stenosis portion of a blood vessel.

  Conventionally, a treatment for expanding a stenosis of a blood vessel by inserting a catheter into the blood vessel has been performed. For example, in coronary angioplasty (PTCA), in order to expand the stenotic part of the coronary artery with a balloon catheter, first, a sheath introducer is inserted into the arterial blood vessel by the Seldinger method, etc. Insert the guide wire as close as possible to the heart. Next, the guiding catheter is inserted so as to be guided by the contrast guide wire, and the distal end thereof is positioned at the coronary artery entrance. Thereafter, the imaging guide wire is removed, and a PTCA guide wire (hereinafter also simply referred to as “guide wire”) is inserted into the guiding catheter, and the tip thereof is positioned near the stenosis. The balloon catheter is inserted into the guiding catheter so as to be guided by the guide wire, and the balloon portion is positioned in the stenosis portion of the coronary artery. Then, the balloon portion is inflated to expand the narrowed portion of the coronary artery (see Patent Documents 1 to 3).

  The balloon catheter has an over-the-wire type (OTW type) provided with a guide wire lumen over its entire length and a guide wire lumen provided only on the distal end side. There is a high-speed exchange type (RX type) in which the base end side of the balloon opens in the middle of the balloon catheter.

  In the RX type balloon catheter, since the guide wire is inserted through the guide wire lumen only at the distal end side of the balloon catheter, the proximal end side of the balloon catheter cannot be expected to be reinforced by the guide wire. As a result, the RX type balloon catheter may be bent when inserted into a blood vessel. In order to solve such a problem, a configuration in which a core wire is provided as a core material in an internal space of an RX type balloon catheter is known (see Patent Documents 4 and 5).

JP 2006-326226 A JP 2007-20737 A JP 2009-536546 A JP 2003-102841 A Japanese Patent Laid-Open No. 2002-736

  However, even the above-described balloon catheter having a core wire has a problem that bending (kinks) easily occurs when inserted into a blood vessel, and operability is not good for guiding the tip to a desired blood vessel. For example, in Patent Documents 4 and 5, the shaft is reinforced by providing a core wire or the like in the shaft, but only one of both ends of the core wire is fixed to the shaft.

  This invention is made | formed in view of the situation mentioned above, The objective is to provide the balloon catheter excellent in operativity.

  The balloon catheter according to the present invention is provided with an elastically inflatable balloon on the distal end side, a distal shaft having an internal space communicating with the internal space of the balloon, an intermediate shaft coupled to the distal shaft, A proximal shaft connected to the intermediate shaft, a guide wire tube provided in the inner space of the distal shaft, and a fixing tube provided on the outer wall of the guide wire tube or the inner wall of the distal shaft. A wire rod having a distal end side inserted into the fixing tube and a proximal end side fixed to the proximal end shaft and inserted into the internal space of the intermediate shaft.

  The balloon catheter is inserted into a blood vessel having a stenotic portion to be expanded. A guide wire is inserted into the blood vessel in advance. This guide wire is inserted into the guide wire tube of the balloon catheter before the balloon catheter is inserted into the blood vessel. The practitioner inserts a balloon catheter into the blood vessel along the guide wire. A wire rod is inserted into the inner space of the distal shaft of the balloon catheter, the distal end side of the wire rod is inserted into the fixing tube, and the proximal end side is fixed to the proximal shaft. Even if the intermediate shaft is curved, the wire does not run out in the internal space of the tip shaft.

  According to the balloon catheter according to the present invention, since the distal end side of the wire is inserted into the fixing tube and the proximal end side of the wire is fixed to the proximal shaft, the wire remains inside the distal shaft even if the intermediate shaft is curved. There is no rampage in space. Thereby, the balloon catheter excellent in operability is realized.

FIG. 1 is a diagram showing an external configuration of the balloon catheter 10 in a state where the balloon 11 is in a contracted posture. FIG. 2 is a partial cross-section of the balloon catheter 10. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a partial cross-sectional view showing a state where the balloon catheter 10 is bent. FIG. 5 is a cross-sectional view of a balloon catheter 10 according to a modification.

  Hereinafter, preferred embodiments of the present invention will be described. In addition, this embodiment is only one embodiment of this invention, and it cannot be overemphasized that an embodiment can be changed in the range which does not change the summary of this invention.

  As shown in FIGS. 1 and 2, the balloon catheter 10 according to the present embodiment includes a shaft 12 having a balloon 11 provided on the distal end side. In the shaft 12, the distal shaft 21, the intermediate shaft 22, and the proximal shaft 23 are connected together along the same axial direction 101 from the distal end to the proximal end. In FIG. 1, the balloon catheter 10 with the guide wire 20 inserted therein is shown, but in FIG. 2, the guide wire 20 is omitted.

  In the present embodiment, the proximal end side refers to the rear side (right side in FIG. 1) with respect to the direction in which the balloon catheter 10 is inserted into the blood vessel. The distal end side refers to the front side (left side in FIG. 1) with respect to the direction in which the balloon catheter 10 is inserted into the blood vessel.

  The shaft 12 is a member that is long in the axial direction 101 as a whole. The shaft 12 is a tubular body that can be elastically bent so as to be bent with respect to the axial direction 101. The direction in which the shaft 12 in the uncurved state extends is referred to as the axial direction 101 in this specification. As a material of the tip shaft 21 and the intermediate shaft 22, for example, synthetic resin can be used. As the material of the proximal shaft 23, for example, stainless steel can be used. Therefore, the proximal shaft 23 has higher bending rigidity than the intermediate shaft 22. In addition, as a material of each shaft, a known material used for a balloon catheter can be used in addition to a synthetic resin, stainless steel, and the like, and it is not always necessary to be composed of only one type of material. A plurality of parts may be assembled and configured.

  An intermediate shaft 22 is fitted and fused to the distal end shaft 21 from the outer side to the proximal end side. Further, the intermediate shaft 22 is fitted and bonded to the distal end side of the proximal end shaft 23 from the outside. The internal spaces of the distal shaft 21, the intermediate shaft 22, and the proximal shaft 23 are in communication. Note that the outer diameter and inner diameter of the shaft 12 vary by about the thickness of the distal shaft 21, the intermediate shaft 22, and the proximal shaft 23.

  A balloon 11 is provided on the distal end side of the distal shaft 21. The balloon 11 is elastically expanded when a fluid (liquid, gas) flows into the internal space, and contracts when the fluid flows out from the internal space. 1 and 2 show the balloon 11 in a deflated state. The internal space of the balloon 11 is in communication with the internal space of the tip shaft 21. When fluid flows into the internal space of the balloon 11, the balloon 11 expands in a radial direction orthogonal to the axial direction 101 so that the center of the axial direction 101 becomes the maximum diameter. As the material of the balloon 11 and the method for fixing the balloon 11 and the distal shaft 21, known materials and methods used in balloon catheters can be used.

  A hub 13 is provided at the base end of the base end shaft 23. The hub 13 is formed with a hole communicating with the internal space of the proximal shaft 23. Through the hub 13, a fluid (gas, liquid) for inflating the balloon 11 flows into or out of the proximal shaft 23.

  As shown in FIG. 2, a guide wire tube 14 is provided in the internal space of the tip shaft 21. The guide wire tube 14 is provided from the distal end of the balloon 11 to the vicinity of the proximal end of the distal shaft 21. That is, the balloon catheter 10 is RX type.

  By providing the guide wire tube 14, the distal end side of the shaft 12, that is, the distal shaft 21 has a double tube structure. The balloon 11 is fixed to the tip of the tip shaft 21. The distal end side of the guide wire tube 14 passes through the internal space of the balloon 11 and is fixed to the balloon 11 at the distal end of the balloon 11. The proximal end of the guide wire tube 14 does not reach the proximal end of the intermediate shaft 22. The proximal end of the guide wire tube 14 is opened outward on the outer wall of the distal shaft 21. Through this opening, the guide wire 20 can be inserted into the guide wire tube 14 from the outside of the shaft 12. As the material of the guide wire tube 14 and the method of fixing the balloon 11 and the tip shaft 21, known materials and methods used in balloon catheters can be used.

  On the distal end side of the balloon 11 and outside, a distal tip 15 is provided continuously with the guide wire tube 14. The distal tip 15 is a synthetic resin molded product having a flexibility that does not damage the inner wall of the blood vessel, and is welded to the distal end side of the balloon 11. The internal space of the tip 15 is in communication with the guide wire tube 14.

  As shown in FIGS. 2 and 3, a fixing tube 17 is provided in the internal space of the tip shaft 21. The fixing tube 17 is fixed to the outer wall on the proximal end side of the guide wire tube 14. The fixing tube 17 extends along the axial direction 101 like the guide wire tube 14. The inner diameter of the fixing tube 17 corresponds to the outer diameter of the wire 16 and is slightly larger than the outer diameter of the wire 16. Since the wire rod 17 is thinner than the guide wire 20, the inner diameter of the fixing tube 17 is smaller than the inner diameter of the guide wire tube 14. Examples of the material of the fixing tube 17 include synthetic resin that can be welded to the guide wire tube 14. The material and the method of fixing the guide wire tube 14 to the guide wire tube 14 may be known materials and methods used in balloon catheters. Can be used.

  A wire 16 is provided in the internal space of the intermediate shaft 22. The wire 16 has a length capable of connecting the distal shaft 21 and the proximal shaft 23. The cross-sectional shape of the wire 16 is a circle, a polygon, or the like, and may have the same outer dimension from the distal end to the proximal end, or may be narrowed so as to become thinner toward the distal end side, for example. The wire 16 has a bending rigidity equal to or higher than that of the intermediate shaft 22 and the guide wire tube 14. Since the outer diameter of the wire 16 is sufficiently smaller than the inner diameter of the intermediate shaft 22, the wire 16 does not block the fluid flowing in the inner space of the tip shaft 21 and the intermediate shaft 22. As a material of the wire 16, for example, a metal such as medical stainless steel can be used.

  The distal end side of the wire 16 is inserted through the fixing tube 17. The gap between the distal end side of the wire 16 and the fixing tube 17 is narrow, and the wire 16 can move slightly in the axial direction with respect to the fixing tube 17, but is almost in the radial direction of the fixing tube 17. I can't move. The proximal end side of the wire 16 is fixed on the distal end side of the proximal end shaft 23 by a known method such as welding or adhesion. Portions other than the distal end side and the proximal end side of the wire 16 are not fixed to the intermediate shaft 22 and the guide wire tube 14 or the like.

[Method of using balloon catheter 10]
Below, the usage method of the balloon catheter 10 is demonstrated.

  Balloon catheter 10 is inserted into a blood vessel to dilate the stenosis. A guide wire 20 is inserted into the blood vessel in advance to reach the stenosis. Such insertion of the guide wire 20 is performed by a known method disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-326226 or Japanese Patent Application Laid-Open No. 2006-230442.

  When the balloon catheter 10 is inserted into the blood vessel, no fluid is pressed into the balloon 11, and the balloon 11 is in a deflated state. From the distal end of the balloon catheter 10 in this state, the proximal end of the guide wire 20 is inserted into the guide wire tube 14 and passed through the proximal end of the guide wire tube 14 opened in the outer wall of the shaft 12. Then, the balloon catheter 10 is inserted into the blood vessel along the guide wire 20. The insertion position of the balloon catheter 10 in the blood vessel is grasped by, for example, confirming the marker embedded in the distal tip 15 with radiation.

  The practitioner grasps the curved state of the blood vessel and operates the hub 13 of the balloon catheter 10. As shown in FIG. 4, the intermediate shaft 22 is elastically curved along the blood vessel as the balloon catheter 10 passes through the curved portion of the blood vessel. Since the distal end side of the wire rod 16 is inserted into the fixing tube 17 and the proximal end side is fixed to the proximal shaft 23, the distal end of the wire rod 16 remains at the distal shaft 21 even if the wire rod 16 is elastically curved along the blood vessel. In the internal space, there is no large displacement in the axial direction 101 or no movement in the radial direction. Therefore, the pushing force applied to the hub 13 side is efficiently transmitted to the distal end side from the curved portion, that is, the distal end shaft 21, so that the force is easily transmitted to the distal end of the balloon catheter 10.

  In this manner, after the balloon catheter 10 is inserted into the blood vessel and reaches the balloon 11 to the narrowed portion of the blood vessel, the balloon 11 is expanded by the fluid being pressed in from the hub 13. Then, the narrowed portion is expanded by the expanded balloon 11.

[Operational effects of this embodiment]
According to the balloon catheter 10 according to the present embodiment, since the distal end side of the wire 16 is inserted through the fixing tube 17 and the proximal end side of the wire 16 is fixed to the proximal shaft 23, the intermediate shaft 22 is curved. The tip end side of the wire 16 does not run out in the internal space of the tip shaft 21. Thereby, the balloon catheter 10 excellent in operability is realized.

[Modification]
In the embodiment described above, the fixing tube 17 is welded to the outer wall of the guide wire tube 14. However, as shown in FIG. 5, the fixing tube 17 is welded to the inner wall of the tip shaft 21. The distal end side of the wire 16 may be inserted through the fixing tube 17.

  In the embodiment described above, each of the distal shaft 21, the intermediate shaft 22, and the proximal shaft 23 is configured as one member. However, the distal shaft 21, the intermediate shaft 22, or the proximal shaft 23 is a plurality of members. May be configured. For example, the tip shaft 21 may be configured by sequentially connecting the single lumen shaft 31, the double lumen shaft 32 having the fixing tube 17 and the single lumen shaft 33 by welding or the like from the tip side.

DESCRIPTION OF SYMBOLS 10 ... Balloon catheter 11 ... Balloon 12 ... Shaft 14 ... Guide wire tube 16 ... Wire rod 17 ... Fixing tube 21 ... End shaft 22 ... Intermediate shaft 23 ..Base shaft

Claims (3)

A balloon that is elastically inflatable is provided on the tip side, and a tip shaft in which the internal space communicates with the internal space of the balloon;
An intermediate shaft coupled to the tip shaft;
A proximal shaft coupled to the intermediate shaft;
A guide wire tube provided in the internal space of the tip shaft;
A fixing tube provided on the outer wall of the guide wire tube or the inner wall of the tip shaft;
A balloon catheter comprising: a wire rod having a distal end side inserted into the fixing tube and a proximal end side fixed to the proximal shaft, and inserted into an internal space of the intermediate shaft.   The balloon catheter according to claim 1, wherein the intermediate shaft has lower bending rigidity than the proximal shaft.   The balloon catheter according to claim 1 or 2, wherein an inner diameter of the fixing tube is smaller than an inner diameter of the guide wire tube.

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