JP2005211492A - Balloon winding method of balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a balloon winding method of a balloon catheter capable of reducing an outer diameter of a wound balloon more than a conventional method. <P>SOLUTION: When winding the balloon of the balloon catheter on a catheter tube of the balloon catheter, the balloon is put under reduced pressure when winding the balloon and/or after winding the balloon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a balloon winding method for winding a balloon around a catheter tube of a balloon catheter, and more particularly to a balloon winding method that can reduce the outer diameter of the wound balloon.

  In recent years, balloon catheters including a catheter tube and a balloon are frequently used for the purpose of treating and examining patients. There are various types of balloon catheters. For example, balloon catheters used for intra-aortic balloon pumping (hereinafter sometimes referred to as IABP) are known.

  The IABP method is a treatment method for assisting cardiac function by increasing the blood pressure in the aorta by inserting a balloon catheter into the aorta and expanding and contracting the balloon in accordance with the pulsation of the heart. The balloon catheter used in the IABP method is usually made of a material having a large outer diameter when the balloon is expanded compared to the outer diameter of the catheter tube, and the balloon is poorly stretchable. A relatively large wrinkle is formed in. The balloon catheter is inserted into the blood vessel in a state where the balloon in the shape of a hook is wound around the catheter tube so that the hook does not get in the way.

As a winding method that can reduce the outer diameter of the wound balloon, a method is known in which the balloon is folded along a vertical folding line and the folded balloon is wound around a catheter tube ( Patent Document 1).
Japanese Patent Laid-Open No. 62-114565

  However, even with a balloon catheter in which a balloon is wound by this method, it is difficult to sufficiently reduce the outer diameter of the wound balloon. When inserting the balloon catheter into a patient, a relatively large perforation is required. It was necessary to provide. If the perforation is large, not only will the burden on the patient increase, but it will take time for hemostasis after the operation, and the operator's effort will be excessive, so the balloon can be made smaller in outer diameter. A winding method was desired.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a balloon winding method of a balloon catheter that can reduce the outer diameter of the wound balloon as compared with the conventional method. .

  As a result of intensive studies to achieve the above object, the present inventors have found that air is entrained between balloon membranes when the balloon is wound around the catheter tube of the balloon catheter, and this entrained air is wound. The present inventors have found that this is a factor for increasing the outer diameter of the balloon, and based on this finding, the present invention has been completed.

  That is, according to the present invention, there is provided a balloon winding method for placing a balloon under reduced pressure at the time of winding the balloon catheter and / or after the balloon winding when the balloon of the balloon catheter is wound around the catheter tube of the balloon catheter. Is done.

  After the balloon is wound around the catheter tube, the wound balloon is covered with a cylindrical sheath, and then the wound balloon is placed under reduced pressure so that the sheath is contracted to adhere to the wound balloon. It is preferable to make it.

  The sheath is preferably a heat shrinkable tube. It is also preferable that the sheath is a tube swollen with a solvent.

  According to another invention of the present invention, a balloon catheter is provided in which a balloon is wound around a catheter tube by the balloon winding method. This balloon catheter is preferably used for intra-aortic balloon pumping.

  ADVANTAGE OF THE INVENTION According to this invention, the balloon winding method of the balloon catheter which can make the outer diameter of the wound balloon small can be provided compared with the conventional method.

  The balloon catheter to which the balloon winding method of the present invention can be applied is not particularly limited as long as it includes a balloon and a catheter tube. For example, a balloon catheter for IABP method, percutaneous coronary angioplasty (PTCA) balloon catheter, percutaneous angioplasty (PTA) balloon catheter, nipple dilatation balloon catheter, and the like. In particular, it is preferable to apply the present invention to a balloon catheter having a relatively large balloon whose outer diameter when expanded exceeds 10 mm, since the effect of reducing the outer diameter of the wound balloon appears remarkably. Examples of the balloon catheter having such a balloon include a balloon catheter for intra-aortic balloon pumping (IABP).

In the balloon winding method of the present invention, the balloon is wound when the balloon is wound around the catheter tube of the balloon catheter (when the balloon is wound) and / or after the balloon is wound around the catheter tube (after the balloon is wound). Is placed under reduced pressure. When the balloon is placed under reduced pressure when the balloon is wound, the amount of air sandwiched between the wound balloon membranes can be reduced. Even when the balloon is wound under normal pressure, the air sandwiched between the wound balloon membranes is discharged by placing the balloon under reduced pressure after the balloon is wound. In either case, since the amount of air sandwiched between the membranes of the wound balloon is reduced, the outer diameter of the wound balloon can be reduced. Note that placing the balloon under reduced pressure refers to lowering the atmospheric pressure on the outer peripheral surface side of the balloon with respect to normal pressure, and the atmospheric pressure on the outer peripheral surface side of the balloon during decompression is preferably 90 kPa or less, More preferably, it is 50 kPa or less, and further preferably 20 kPa or less. By setting the air pressure on the outer peripheral surface side of the balloon to a predetermined value or less, the outer diameter of the wound balloon can be made thinner. The lower limit of the atmospheric pressure on the outer peripheral surface side of the balloon at the time of decompression is not particularly limited, but is usually 1.0 × 10 ⁻¹⁰ kPa.

  In the present invention, the method of winding the balloon is not particularly limited, and the balloon may be deflated so as to be planar, and the planar balloon may be wound around the catheter tube, or three balloons may be wound. These balloons may be contracted so as to have the above-mentioned ridges, and these balloons may be wound around the catheter tube. Alternatively, the deflated balloon may be folded, and the folded balloon may be wound around the catheter tube.

  As a method of placing the balloon under reduced pressure and winding the balloon around the catheter tube, for example, the whole balloon catheter is placed in a vacuum glove box, the inside of the vacuum glove box is depressurized, and then the balloon deflated into the catheter tube is used. The method of winding is mentioned. Further, by this method, after winding the balloon and before taking out the balloon catheter from the vacuum glove box, a cylindrical sheath having an inner diameter substantially equal to the outer diameter of the wound balloon is attached to the wound balloon. It is preferable to cover it. By covering the balloon wound in this manner with the sheath, it is possible to prevent the wound balloon from increasing in outer diameter due to air entering between the balloon membranes after the balloon is taken out under normal pressure.

  Examples of the method of placing the wound balloon under reduced pressure after winding the balloon under normal pressure include a method of placing a balloon catheter wound with a balloon in a vacuum box or a vacuum dryer. These methods are preferable because the balloon can be wound under normal pressure and the workability is good.

  In the method of placing the balloon under reduced pressure after winding the balloon under normal pressure, the balloon is wound on the catheter tube of the balloon catheter, and then the wound balloon is covered with a cylindrical sheath, and then the wound balloon It is preferable that the sheath is contracted while being placed under reduced pressure to be in close contact with the wound balloon. According to this method, since the balloon wound with the sheath is pressed under reduced pressure, the discharge of the air caught between the balloon membranes is promoted, and the outer diameter of the wound balloon can be further reduced. . Further, since the balloon wound with the sheath is tightened, it is possible to prevent the outer diameter of the wound balloon from becoming large due to air entering between the balloon membranes after the balloon is taken out under normal pressure.

  The tubular sheath is not particularly limited as long as it is a shrinkable tubular body, but it is preferable to use a heat shrinkable tube or a tube swollen with a solvent. Since the inner diameter of these tubes is reduced by heating, the sheath can be contracted by placing the wound balloon as a sheath and then placing it in a vacuum drier while placing the balloon under reduced pressure. The inner diameter of these sheaths before contraction is preferably 100 to 300% of the outer diameter of the balloon wound under normal pressure. If the inner diameter of the sheath before contraction is too small, it will be difficult to cover the wound balloon with the sheath, and if it is too large, it will be difficult to cause the sheath to contract sufficiently and adhere to the wound balloon. Moreover, it is preferable that the shrinkage rate of the internal diameter of these sheaths is 10 to 70%.

  The heat shrinkable tube used as the sheath is preferably one that shrinks when heated to 40 to 80 ° C. By using the heat-shrinkable tube having a relatively low contraction temperature in this way, it is possible to prevent the quality of the balloon catheter from being deteriorated by heating the balloon. The type of heat-shrinkable tube is not particularly limited. Vinyl chloride-based heat-shrinkable tube, polyolefin-based heat-shrinkable tube, silicone rubber-based heat-shrinkable tube, fluororesin-based heat-shrinkable tube, ethylene-propylene rubber-based heat-shrinkable tube, polyester-based A heat shrinkable tube or the like can be used, and it is particularly preferable to use a silicone rubber heat shrinkable tube.

  When the tube swollen with a solvent is used as the sheath, the material of the tube is not particularly limited as long as it can be swollen with any solvent, but it is preferable to use a silicone resin. As a solvent used for swelling, a solvent having a relatively low boiling point is preferable, and a solvent having a boiling point of 40 to 80 ° C. is particularly preferable. By using a solvent having a relatively low boiling point in this way, the sheath can be contracted at a low temperature, so that it is possible to prevent the balloon catheter from being deteriorated by heating. Examples of the solvent to be used include hexane, ethanol, chlorofluorocarbon solvents, and alternative chlorofluorocarbon solvents. It is particularly preferable to use hexane. It is also preferable to use water as a solvent after using a water-swellable resin such as water-swellable polyurethane as the material of the tube without using such an organic solvent.

  The sheath used in the balloon winding method of the present invention tends to adhere strongly to the wound balloon, and it may be difficult to remove the balloon from the sheath when using the balloon catheter. It is preferable to provide the sheath with a sheath in advance. If this means is provided, even when the balloon cannot be pulled out of the sheath, the sheath can be torn and removed. Examples of means for facilitating the tearing of the sheath include perforations and notches.

  In the balloon winding method of the present invention, one sheath may be covered over the entire balloon, or a plurality of sheaths may be covered.

  In addition, the balloon of the balloon catheter to which the balloon winding method of the present invention is applied is preliminarily attached with a crease for desired winding in order to prevent unwinding during the operation. It is preferable to carry out. The balloon can be kneaded by winding the balloon into a desired shape and fixing it by covering the tube, and then heating.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking as an example the case of application to a balloon catheter used in the IABP method.

[Intra-aortic balloon catheter]
First, the intra-aortic balloon catheter 1 used in this example will be described. An intra-aortic balloon catheter 1 shown in FIG. 1 is used for the IABP method, and is attached to a catheter tube 10 including an outer tube 11, an inner tube 12, and a connector 13, and a distal end portion of the catheter tube 10. The balloon 20 and the tip 30 joined to the distal end of the balloon 20 are formed.

  The catheter tube 10 of the intra-aortic balloon catheter 1 includes an outer tube 11, an inner tube 12 and a connector 13. The inner tube 12 extends in the axial direction into the outer tube 11, and the distal end of the inner tube 12 projects from the outer tube 11. The outer peripheral surface of the inner tube 12 in the outer tube 11 is bonded to the inner peripheral surface of the outer tube 11 with an adhesive, and the proximal end of the inner tube 12 and the proximal end of the outer tube 11 are both connectors 13. It is connected to the.

  The outer tube 11 constituting the catheter tube 10 of the intra-aortic balloon catheter 1 is made of polyamide, has an outer diameter of 2.0 mm, a wall thickness of 0.11 mm, and an axial length of 510 mm. The inner tube 12 constituting the catheter tube 10 is made of polyetheretherketone, has an outer diameter of 0.57 mm, a wall thickness of 0.1 mm, and an axial length of 720 mm. The connector constituting the catheter tube 10 is made of ABS resin.

  The balloon 20 of the intra-aortic balloon catheter 1 has an expansion / contraction portion 21 that is expanded / contracted by introduction / extraction of fluid through the fluid flow path 14 of the catheter tube 10 and a distal end side of the expansion / contraction portion 21. It is a cylindrical body composed of a distal end portion 22 positioned and a proximal end portion 23 positioned on the proximal end side of the expansion / contraction portion 21. The distal end portion 22 and the proximal end portion 23 of the balloon 20 are used as joint margins for attaching the balloon 20 to the distal end portion of the catheter tube 10, and are portions that are not expanded or contracted by a fluid. The expansion / contraction part 21 of the balloon 20 is provided with a distal end side taper part 24 and a proximal end side taper part 25 extending in a tapered shape toward the distal end part 22 and the proximal end part 23. .

  The balloon 20 of the intra-aortic balloon catheter 1 is obtained by molding a polyurethane elastomer by a dip molding method, and the film thickness of the balloon 20 is 60 μm. Moreover, the internal capacity | capacitance of the expansion / contraction part 21 is 30 cc, the outer diameter at the time of expansion is 13 mm, and the axial direction length is 210 mm.

[Kusashi]
Next, a description will be given of the caulking of the balloon 20 that is performed in order to easily wind the balloon 20 of the aortic balloon catheter 1 around the catheter tube 10. FIG. 2 is a schematic view showing a method for attaching the balloon 20. First, as shown in FIG. 2A, the syringe 60 was attached to the port 15 of the connector 13, and the syringe 60 was pulled, whereby the inside of the balloon 20 was decompressed and contracted so that the balloon 20 became flat. Next, after adjusting the shape of the balloon 20 so that the inner tube 12 is positioned at the position of the central axis of the balloon 20 that has become flat, as shown in FIG. 2B and FIG. The balloon membranes located on both the left and right sides were wound around the inner tube 12 (catheter tube 10) so as to have the same rotational direction. Next, a fixing tube 70 (made of polyethylene, inner diameter: 2.4 mm, outer diameter: 4.3 mm, length: 120 mm) is covered from the distal end side of the balloon 20 wound as shown in FIG. The half on the proximal end side of the balloon 20 was covered. Then, the same operation is repeated, so that the other half of the balloon 20 is covered with the other fixing tube 70 and the wound balloon 20 is entirely covered with the two fixing tubes 70. did.

  Then, the balloon catheter 1 is put into an oven (not shown), heated to 70 ° C. for 6 hours, allowed to cool, and the fixing tube 70 is removed. As shown in FIG. A balloon catheter 1 in which 20 is wound into a wound shape is obtained.

〔Example〕
Examples of the present invention will be described in detail below. FIG. 4 is a schematic view showing a balloon winding method in the present embodiment. First, a perforation 41 was provided along the axial direction in a heat-shrinkable tube made of silicone rubber having an inner diameter of 3.0 mm, an outer diameter of 4.0 mm, and a length of 240 mm for use as a sheath 40 that covers the wound balloon 20.

  Next, the balloon 20 attached to the wound shape of the balloon catheter 1 shown in FIG. 4 (A) is placed in the sheath 40 (heat-shrinkable tube) as shown in FIG. 4 (B). The sheath 40 was put on the wound balloon 20 by being inserted from the side.

  Then, as shown in FIG. 4 (C), the balloon 20 wound with the balloon catheter 1 is put into the vacuum dryer 50, the inside of the vacuum dryer 50 is depressurized to 8 kPa, and then heated to 60 ° C. Then, the sheath 40 was contracted. After 1 hour, the inside of the vacuum dryer 50 was returned to normal pressure (1.013 kPa) and 25 ° C., and the balloon 20 was allowed to cool.

  Then, the balloon 20 is taken out from the vacuum dryer 50, the sheath 40 is cut along the perforation 41, and immediately after the balloon 20 is removed from the balloon 20, the outer diameter of the wound balloon 20 is reduced at the central portion in the longitudinal direction of the balloon 20. When measured, the outer diameter was 1.88 mm.

[Comparative example]
The syringe 60 was connected to the port 15 of the balloon catheter 1 used in the example, air was sent in, and the balloon 20 was expanded to unwind the balloon 20. Subsequently, the balloon 20 of the balloon catheter 1 is wound around in the same manner as in the example except that the inside of the vacuum dryer 50 is not decompressed and the atmospheric pressure in the vacuum dryer 50 is maintained at normal pressure (101.3 kPa). Went. Then, the balloon catheter 1 is taken out from the vacuum dryer 50, the sheath 40 is cut along the perforation 41, and immediately after being removed from the balloon 20, the outer diameter of the wound balloon 20 is measured. 2.20 mm.

FIG. 1 is an overall view showing the structure of an intra-aortic balloon catheter according to an embodiment of the present invention. FIG. 2 is a schematic view showing a method for attaching balloons in the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a state before and after the balloon is wound around the inner tube of the intra-aortic balloon catheter in the embodiment of the present invention. FIG. 4 is a schematic view showing a winding method of an intra-aortic balloon catheter in the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intra-aortic balloon catheter 10 Catheter tube 11 Outer tube 12 Inner tube 13 Connector 14 Fluid flow path 15 Port 20 Balloon 21 Expansion contraction part 22 Distal end part 23 Proximal end part 24 Distal end side taper part 25 Proximal end side Tapered portion 30 Tip tip 40 Sheath 41 Perforation 50 Vacuum dryer 60 Syringe 70 Fixing tube

Claims (6)

A balloon winding method in which a balloon of the balloon catheter is wound under a reduced pressure when the balloon of the balloon catheter is wound around the catheter tube of the balloon catheter. After the balloon is wound around the catheter tube, the wound balloon is covered with a cylindrical sheath, and then the wound balloon is placed under reduced pressure so that the sheath is contracted to adhere to the wound balloon. The balloon winding method according to claim 1. The balloon winding method according to claim 2, wherein the sheath is a heat shrinkable tube. The balloon winding method according to claim 2, wherein the sheath is a tube swollen with a solvent. A balloon catheter in which a balloon is wound around a catheter tube by the balloon winding method according to claim 1. The balloon catheter according to claim 5, which is used for intra-aortic balloon pumping.

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