JP2014226178A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter where an occurrence of kink or the like is prevented and excellent pushability is performed.SOLUTION: A balloon catheter 10 includes a shaft 12 comprising a proximal shaft 16 at a proximal end part and a distal shaft 18 at a distal end part, and is composed of an outer shaft 22 where the distal shaft is provided with a supplying/discharging lumen and an inner shaft 24 provided with a guide wire lumen. To the distal end part of the inner shaft, a distal end part of a balloon 14 is fixed; with the balloon, the supplying/discharging lumen of the outer shaft is communicated; a wire material 36 projecting from the distal end of the proximal shaft is provided and a proximal end of the wire material is fixed to the proximal shaft; and the distal end of the wire material is fixed to the inner shaft of the distal shaft. In the balloon catheter 10, there is provided a material or structure in which the inner shaft of the distal shaft is harder to expand than the outer shaft of the distal shaft.

Description

  The present invention relates to a balloon catheter having a balloon at a distal end portion of a shaft.

  Conventionally, a balloon catheter has been used to expand and deform a stenosis portion of a blood vessel or to expand and deform a stent in, for example, percutaneous coronary intervention (PCI). The balloon catheter has, for example, a structure in which a balloon is provided at a distal end portion of a shaft constituted by a proxy shaft and a distal shaft, and a supply / exhaust lumen communicating with the balloon is provided. . Then, when the fluid is supplied through the supply / discharge lumen while the balloon is inserted into the stenosis portion of the blood vessel, the balloon is inflated and the stenosis portion is expanded and deformed.

  The balloon catheter includes an over-the-wire type (OTW type) and a rapid exchange type (RX type) in which balloons can be easily exchanged. In this rapid exchange type balloon catheter, a distal shaft is composed of an outer shaft and an inner shaft, a balloon is provided on the outer shaft to form a supply / discharge lumen, and the inner shaft is a tip surface of the outer shaft. And an outer peripheral surface of the intermediate portion are provided so as to be opened, and a guide wire lumen through which the guide wire is inserted is formed (Patent Document 1 or 2).

JP 2003-164528 A JP 2001-333984 A

  However, in the balloon catheter of Patent Document 1 or 2, there is a possibility that the distal shaft may extend if it is forcibly pulled when the balloon catheter is recovered from the guiding catheter or the sheath in a state where the balloon is not sufficiently contracted. Further, even when the distal end of the catheter is caught in the stenosis, it is possible that the distal shaft may be extended.

  As a result, the balloon catheter may not be reusable, the balloon cannot be deflated, resulting in an ischemic state, or, as a worst case, a broken piece may remain in the blood vessel.

  A first aspect of the present invention is a shaft composed of a proximal shaft at a proximal end portion and a distal shaft at a distal end portion, wherein the distal shaft includes an outer shaft having a supply / discharge lumen. And an inner shaft with a guide wire lumen, the distal end portion of the inner shaft being fixed to the distal end portion of the balloon, and the supply and discharge lumen of the outer shaft being in communication with the balloon A wire projecting from the distal end of the proximal shaft is provided, the proximal end of the wire is fixed to the proximal shaft, and the distal end of the wire is fixed to the inner shaft of the distal shaft In the balloon catheter, the inner shaft of the distal shaft has a material or structure that is less likely to extend than the outer shaft of the distal shaft. That there was example, it is characterized.

  According to the rapid exchange type balloon catheter having the structure according to the first aspect as described above, the proximal shaft and the inner shaft are connected to each other by the wire, so that the proximal shaft is distant from the proximal end side of the proximal shaft. An external force (tensile force) exerted toward the distal end side is efficiently transmitted to the inner shaft through the wire. In addition, since the inner shaft has a material or structure that is less likely to extend than the outer shaft, the shaft does not extend over the entire length. Therefore, in the case of recovering the balloon catheter from the guiding catheter or the sheath in a state where the balloon is not sufficiently contracted, a balloon catheter in which the distal shaft is difficult to extend can be realized. Further, it is possible to realize a balloon catheter in which the distal shaft is not easily stretched even when the distal end of the catheter is caught in the stenosis part or forcibly pulled.

  Further, in a general rapid exchange type balloon catheter, the strength in the axial direction of the distal shaft at the formation portion of the proximal end side opening portion of the guide wire lumen (port which is the proximal end side opening portion of the inner shaft). , It is easy to decrease, so that problems such as kinks may occur due to the action of the pushing force. However, in the rapid exchange type balloon catheter according to this aspect, since the wire material is arranged so as to straddle the port formation portion, the port formation portion of the distal shaft is reinforced with the wire material to prevent the occurrence of kinks, etc. Is done. As a result, the pushing force is prevented from being reduced by the deformation of the shaft, and excellent pushability is realized.

  According to the present invention, even if the rapid exchange type balloon catheter is caught (stacked) at any part of its length, it can be recovered from the guiding catheter or sheath without extending the shaft. In addition, if the material or structure is less likely to extend than the inner shaft, the distal end of the catheter is connected to the inner shaft even if the outer shaft is not easily extended or collected, so it can be easily recovered when stacked on the stenosis. it can.

The side view which shows the balloon catheter as one Embodiment of this invention. The side view which expands and shows the principal part of the balloon catheter shown by FIG. The top view which expands and shows the principal part of the balloon catheter shown by FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a balloon catheter 10 as one embodiment of the present invention. The balloon catheter 10 includes a shaft 12 and a balloon 14 provided at a distal end portion of the shaft 12. In the following description, the right side in FIG. 1 is referred to as the proximal end, and the left side in FIG. 1 is referred to as the distal end.

  More specifically, the shaft 12 is constituted by a proximal shaft 16 constituting a proximal end portion and a distal shaft 18 constituting a distal end portion. The proxy shaft 16 is a member formed of a material having a relatively large rigidity and having a substantially cylindrical shape with a small diameter. In this embodiment, the proxy shaft 16 is formed of a metal material such as stainless steel. A connector 20 is attached to the proximal end of the proximal shaft 16, and a central hole (lumen) of the proximal shaft 16 opens at the proximal end through the connector 20.

  Moreover, the distal shaft 18 is comprised by the outer shaft 22 and the inner shaft 24, as FIG. 1-3 shows. The outer shaft 22 has a cylindrical shape with a diameter approximately equal to or greater than that of the proxy shaft 16, is formed of a synthetic resin material, and is more flexible than the proxy shaft 16. The outer shaft 22 has a proximal end fixed to the distal end of the proximal shaft 16, and a supply / discharge lumen 26 is formed by the central hole of the outer shaft 22 and the central hole of the proximal shaft 16.

  The inner shaft 24 has a material or structure that is less likely to extend than the outer shaft 22. Examples of the material of the inner shaft 24 include resins such as polyimide, polyetheretherketone, and polyamideimide, and metals such as nickel titanium alloys. Further, examples of the structure of the inner shaft 24 include a tube with a reinforcing wire and a stranded wire tube. Examples of the reinforcing wire-containing tube include a three-layer structure of an inner layer, a metal mesh wire, and an outer layer.

  The inner shaft 24 is tubular, has a smaller diameter than the outer shaft 22, and is inserted into the distal end portion of the outer shaft 22. Further, the distal end portion of the inner shaft 24 protrudes more distally than the outer shaft 22 and is fixed to the distal end portion of the balloon 14, and the proximal end of the inner shaft 24 is the middle of the outer shaft 22. It is fixed to the part and opens to the outer peripheral surface. Thus, the central hole of the inner shaft 24 is a guide wire lumen 28 having a distal end opened to the tip surface and a proximal end opened to the outer peripheral surface of the intermediate portion of the outer shaft 22. The proximal end portion of the inner shaft 24 is formed as a port 30 that extends at an angle with respect to the axial direction (the left-right direction in FIG. 1) and opens to an intermediate portion of the outer shaft 22.

  A cylindrical tip chip 32 made of a relatively hard synthetic resin material is attached to the distal end of the inner shaft 24, and a guide wire lumen 28 opens to the tip surface through the center hole. ing.

  Further, a balloon 14 is provided at the distal end portion of the inner shaft 24. The balloon 14 is a cylindrical or bag-like member formed of a thin film of a synthetic resin material, and has a larger diameter than the inner shaft 24 in an expanded state. The balloon 14 has a proximal end fixed to the distal end of the outer shaft 22 by fusion and the like, and the distal end is fused and integrated to the outer peripheral surface of the distal end portion of the inner shaft 24. Is fixed. In addition, as a balloon, in addition to a stenosis part such as a blood vessel as shown in the present embodiment and a stent that expands and deforms by expanding pressure, a cutting blade is provided on the outer peripheral surface to be calcified. A cutting balloon (such as Japanese Patent Application Laid-Open No. 5-293176) that cuts into the lesioned part, and a helical wire or the like (scoring element) is provided on the outer peripheral surface, and the wire or the like bites into the constricted part. Balloons of various structures such as a scoring balloon (Japanese translations of PCT publication No. 2007-530158) adapted to prevent displacement can be adopted.

  Thereby, a space separated from the outside is formed between the balloon 14 and the inner shaft 24, and a supply / discharge lumen 26 formed in the outer shaft 22 is communicated with the proximal end of the space. When the fluid is supplied to the balloon 14 from the supply / discharge device (not shown) connected to the connector 20 through the supply / discharge lumen 26, the balloon 14 is inflated, and the fluid in the balloon 14 is discharged to the outside through the supply / discharge lumen 26. As a result, the balloon 14 is deflated. At the proximal end portion and the distal end portion of the balloon 14, a radiopaque annular marker 34 made of a metal material is fitted to the inner shaft 24, and is inserted into a blood vessel to be described later. The position of the balloon 14 can be confirmed by contrast.

  In the balloon catheter 10, the proxy shaft 16 and the inner shaft 24 are connected to each other by a connecting wire 36 as a wire. The connecting wire 36 is a solid small-diameter rod-shaped member formed of a metal material such as stainless steel, and its proximal end portion is fixed to the proximal shaft 16 and its distal end portion is an inner shaft. 24 is fixed. The connecting wire 36 has a greater axial rigidity than the distal shaft 18 formed of a synthetic resin material, and deformation such as expansion and contraction is less likely to occur due to the force acting in the axial direction. Yes. The connecting wire 36 may be formed with a substantially constant cross-sectional shape (thickness) from the proximal end to the distal end. More preferably, for example, the connecting wire 36 gradually becomes thinner from the proximal end toward the distal end. It is formed with a taper-shaped wire (with a small cross-sectional area). The connecting wire 36 is preferably formed of a metal material in order to obtain a sufficient strength with a small diameter, but may be formed of a hard synthetic resin material or the like.

  The connecting wire 36 protrudes in a substantially axial direction from the distal end of the proximal shaft 16 by the proximal end portion being superimposed on the inner peripheral surface of the proximal shaft 16 and fixed by means such as welding. It is arranged. In the present embodiment, the entire proxy shaft 16 is formed of a metal material, and an arbitrary portion of the proxy shaft 16 to which the connecting wire 36 is fixed is a proximal fixing portion.

  The inner shaft 24 is provided with a fixing ring 38 as a distal fixing portion. The fixing ring 38 is an annular member formed of a metal material such as stainless steel. In this embodiment, the fixing ring 38 is substantially the same as the annular marker 34 formed of a radiopaque material. ing. The fixing ring 38 is inserted and fixed to the insertion portion of the inner shaft 24 into the outer shaft 22. The fixing ring 38 may be fixed to the inner shaft 24 by means such as adhesion or welding in addition to fitting.

  And the part which protruded from the distal end of the proxy shaft 16 in the connection wire 36 is overlapped on the outer peripheral surface of the fixing ring 38 and fixed by means such as welding, so that the connection wire 36 is attached to the inner shaft 24. On the other hand, it is fixed via a fixing ring 38. The fixing ring 38 is attached to the distal end side of the port 30 of the inner shaft 24, and the connecting wire 36 is disposed across the port 30 in a state where the proxy shaft 16 and the inner shaft 24 are connected. Yes.

  Further, the portion of the connecting wire 36 that protrudes from the distal end of the proximal shaft 16 is disposed so as to be relatively displaceable without being fixed to the outer shaft 22. Thereby, transmission of force between the outer shaft 22 and the connecting wire 36 is prevented. In the present embodiment, the connecting wire 36 has a smaller diameter than the gap in the direction perpendicular to the axis of the outer shaft 22 and the inner shaft 24, and in a stationary state in which the shaft 12 is not deformed by the input of external force, the connecting wire 36 is spaced apart from the outer shaft 22 in the direction perpendicular to the axis.

  The balloon catheter 10 having such a structure is used for, for example, percutaneous coronary intervention (PCI). That is, the guide wire 40 previously inserted into the blood vessel is inserted through the guide wire lumen 28 and the balloon catheter 10 is pushed along the guide wire 40, whereby the balloon 14 is inserted into the stenosis portion of the blood vessel. Thereafter, the balloon 14 is inflated by supplying a fluid to the balloon 14 through the supply / discharge lumen 26, and the stenosis portion is expanded by the inflation pressure of the balloon 14. In addition, the stent is inserted into the stenosis part by inserting the stent into the deflated balloon 14 and inserting the stent into the stenosis part, and expanding and deforming the stent while expanding the stenosis part by expanding the balloon 14. Can also be used for surgery.

  Thus, when the balloon catheter 10 is pushed forward and the balloon 14 is inserted into the stenosis, the pushing force exerted on the connector 20 operated by the practitioner (acting toward the distal end side) The force that pushes the distal end side) is transmitted efficiently toward the distal end side of the distal shaft 18 via the proxy shaft 16.

  That is, the connecting wire 36 fixed to the proximal shaft 16 and protruding from the distal end is fixed to the inner shaft 24, so that the pushing force exerted on the connector 20 by the practitioner causes the proximal shaft 16 to And extends from the proxy shaft 16 to the inner shaft 24 via the connecting wire 36. Thereby, the pushing force exerted by the practitioner is efficiently transmitted to the tip 32 provided at the distal end of the inner shaft 24, and the balloon catheter 10 having excellent pushability that allows easy passage through the stenosis is realized. Is done.

  In addition, the formation portion of the port 30 where strength reduction is likely to be a problem in the distal shaft 18 is reinforced by the connecting wire material 36, thereby preventing the occurrence of bending (kinks) due to exerting a pushing force, The pushing force is effectively transmitted to the distal end.

  Moreover, the connecting wire 36 formed of a metal material is firmly fixed to the proxy shaft 16 formed of a metal material by welding. Therefore, the connecting wire 36 is prevented from coming off the proxy shaft 16 by the action of the tensile force, and the tensile force is effectively transmitted to the proximal end side.

  Furthermore, a fixing ring 38 made of a metal material is fitted and fixed to the inner shaft 24, and a connecting wire 36 made of a metal material is firmly fixed to the fixing ring 38 by welding. Accordingly, the connection between the connecting wire 36 and the inner shaft 24 is prevented from being released by the action of the tensile force, and the tensile force is effectively transmitted to the proximal end side.

  In addition, since the distal fixing portion to which the connecting wire 36 is fixed is the annular fixing ring 38, a sufficiently large fixing force with respect to the inner shaft 24 can be obtained, and the fixing ring 38 with respect to the inner shaft 24 can be obtained. Since displacement is also prevented, transmission of the tensile force to the inner shaft 24 via the connecting wire 36 is effectively realized.

  In particular, since the fixing ring 38 of the present embodiment is the same as the annular marker 34, there is no need to newly prepare a special part as the fixing ring. Facilitation can be achieved.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the material for forming the wire is not limited to a metal material such as stainless steel, and a synthetic resin material or the like may be employed. Moreover, the shape (especially cross-sectional shape) of a wire is not limited, For example, wire materials, such as a rectangular cross section and a deformed cross section, are also employable.

  Also, two or more wire rods may be provided, and the shaft reinforcing effect can be obtained more effectively. In that case, all the wires may be fixed to the inner shaft at the same position in the axial direction, or may be fixed to the inner shaft at different positions.

  Further, in the above-described embodiment, as a method for fixing the wire to the inner shaft 24, a method of welding and fixing the wire to the fixing ring 38 fitted to the inner shaft 24 is exemplified. It is not limited. For example, the wire may be directly superimposed on the outer peripheral surface of the inner shaft 24 and welded and fixed, or may be bonded and fixed using an adhesive.

  Furthermore, the wire may be fixed to the proxy shaft 16 or the inner shaft 24 at two or more locations in the axial direction, thereby realizing stronger fixation.

  Further, the distal-side fixing portion does not need to be configured by a ring-shaped member such as the fixing ring 38, and may be, for example, a curved plate shape that is overlapped and welded to a part of the inner shaft 24. good. Furthermore, the proximal side fixing | fixed part may be provided, for example by forming only the distal end part of the proximal shaft 16 with a metal material. Further, the distal-side fixing portion and the proximal-side fixing portion are not limited to those formed of a metal material, and those formed of a synthetic resin may be employed.

  Moreover, the shaft 12 does not need to be formed only by the proxy shaft 16 and the distal shaft 18, and may be formed by combining three or more shafts. More specifically, a port shaft including a port 30 may be provided between the proxy shaft and the distal shaft. Further, the proxy shaft and the distal shaft do not necessarily have the same central axis, and the central axes may be shifted in the direction perpendicular to the axis. In this case, for example, the port shaft connecting the proxy shaft and the distal shaft extends while being inclined with respect to the axial direction, so that the continuous supply / discharge lumen 26 is secured.

  In the above-described embodiment, one supply / discharge lumen 26 is provided, and both the inflation and deflation of the balloon 14 are executed by the supply / discharge lumen 26. It is also possible to provide independent inflation and deflation lumens.

  In the above embodiment, the inner shaft 24 is fitted with a fixing ring 38 as a distal fixing portion, and the connecting wire 36 is overlapped with the outer peripheral surface of the fixing ring 38 and connected by means such as welding. The inner shaft 24 and the connecting wire 36 may be connected by any other means.

10: balloon catheter, 12: shaft, 14: balloon, 16: proximal shaft, 18: distal shaft, 22: outer shaft, 24: inner shaft, 26: supply / discharge lumen, 28: guide wire lumen, 36: connection Wire rod (wire rod), 38: fixing ring (distal anchoring portion)

Claims (4)

A shaft comprising a proximal shaft at the proximal end portion and a distal shaft at the distal end portion, wherein the distal shaft includes an outer shaft having a supply / discharge lumen and an inner shaft having a guide wire lumen; The distal end portion of the balloon is fixed to the distal end portion of the inner shaft, the supply / discharge lumen of the outer shaft is communicated with the balloon, and the distal end of the proximal shaft A balloon catheter provided with a wire protruding from the proximal end of the wire is fixed to the proxy shaft, and the distal end of the wire is fixed to the inner shaft of the distal shaft;
A balloon catheter characterized in that the inner shaft of the distal shaft is provided with a material or structure that is less likely to extend than the outer shaft of the distal shaft.   The balloon catheter according to claim 1, wherein a material of the inner shaft is a resin material or a metal material which is any one of polyimide, polyetheretherketone, and polyamideimide.   The balloon catheter according to claim 1, wherein the structure of the inner shaft is constituted by a reinforcing wire-containing tube or a stranded wire tube.   The wire is formed of a metal material, a distal fixing portion formed of a metal material is provided on the inner shaft of a distal shaft, and the wire is fixed to the distal fixing portion. The balloon catheter according to any one of 1 to 3.

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