JP4492183B2 - Balloon catheter - Google Patents

Description

  The present invention relates to a balloon catheter, and more particularly to a balloon catheter that is suitably used for intra-aortic balloon pumping.

  In recent years, balloon catheters are frequently used for various treatments and examinations in the medical field. For example, an intra-aortic balloon pumping method (IABP method) is performed as a treatment for lowering cardiac function, in which a balloon catheter is inserted into the aorta, and the balloon is inflated and deflated according to the heart beat to assist the cardiac function. It has been broken.

  As an intra-aortic balloon catheter used in this IABP method, a catheter having a so-called double tube structure formed by an outer tube and an inner tube located inside the outer tube is generally used (for example, (See Patent Document 1 and Patent Document 2).

  In the intra-aortic balloon catheter described in Patent Documents 1 and 2, the inner tube and the outer tube are connected for the purpose of preventing a phenomenon that the catheter becomes difficult to insert into the body due to the relative movement of the inner tube and the outer tube. It is fixed near the tip of the outer tube.

  However, in the method of bonding the outer tube and the inner tube with an adhesive only in the vicinity of the distal end of the outer tube as in the balloon catheter of Patent Document 1, it is difficult to secure a sufficient bonding area, and sufficient bonding strength is obtained. I can't get it. For this reason, the bonded portion may be peeled off during insertion of the balloon catheter.

Further, in the technique in which the inner tube and the outer tube are fixed by inserting another member for fixing inside the outer tube as in the balloon catheter of Patent Document 2, since the other member exists, the outer tube The tip opening surface of the is narrowed. For this reason, the flow path resistance of the fluid for inflating and deflating the balloon increases at the separate member insertion portion, and the time required to inflate and deflate the balloon may become long (responsiveness deteriorates). . If the responsiveness of the balloon is deteriorated, it becomes difficult to inflate and deflate the balloon in accordance with the pulsation of the heart, and the effect of assisting cardiac function is reduced.
JP 2000-5318 A JP 2003-701

  The present invention has been made in view of such a situation, and by simple means, the inner tube and the outer tube are firmly fixed in the vicinity of the distal end of the outer tube, and the opening area at the distal end of the outer tube is large, and the responsiveness. An object of the present invention is to provide a balloon catheter that can inflate and deflate the balloon part well.

In order to achieve the above object, a balloon catheter according to the present invention comprises:
A balloon portion that can be inflated and deflated, and
An outer tube having a tip connected to a rear end of the balloon so as to introduce and lead a pressure fluid into and out of the balloon;
A balloon catheter having a distal end portion of the balloon portion connected and an inner tube extending in the axial direction inside the balloon portion and the outer tube,
In the front end portion of the outer tube, a notch extending in the circumferential direction of the outer tube is formed at a position away from the front end opening surface of the outer tube toward the rear end by a predetermined width,
A notch piece that is a part of the tube wall of the outer tube located between the notch and the tip opening surface is pushed toward the inside of the outer tube, so that the inner tube can be inserted. An engagement hole is formed,
The inner tube is inserted through the engagement hole.

  Preferably, the front end opening surface of the outer tube forms an acute angle with respect to the longitudinal axis of the outer tube.

  Preferably, the notch piece is positioned so as to protrude from the distal end opening surface of the outer tube to the distal end side to form the engagement hole.

  Preferably, the outer diameter of the inner tube positioned on the front end side of the cut piece is larger than the outer diameter of the inner tube positioned on the rear end side of the cut piece.

  The balloon catheter of the present invention is preferably used for intra-aortic balloon pumping.

  According to the present invention, the inner tube and the outer tube are firmly fixed in the vicinity of the distal end of the outer tube by simple means, and the opening area at the distal end of the outer tube is large, and the balloon portion is inflated and contracted with good responsiveness. A balloon catheter that can be made is provided.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

FIG. 1 is a schematic cross-sectional view of a balloon catheter according to an embodiment of the present invention.
FIG. 2 is an enlarged view showing details of an engaging portion between the outer tube and the inner tube shown in FIG.
3 is a schematic perspective view showing a fixed state of the outer tube and the inner tube shown in FIG.
FIG. 4 is a schematic diagram showing a process for making a cut at the tip of the outer tube,
FIG. 5 is a schematic view showing a continuation process of FIG.
FIG. 6 is a cross-sectional view of a principal part taken along line VI-VI in FIG.

Balloon catheter 20 according to an embodiment of the present invention shown in the first embodiment Figure 1 is a balloon catheter for use in the intra-aortic balloon pumping method, having a balloon portion 22 to expand and contract in accordance with the beating of the heart. The balloon part 22 is comprised with the thin film about 50-150 micrometers in film thickness. The material of the thin film is not particularly limited, but is preferably a material excellent in bending fatigue resistance, and is made of, for example, polyurethane. The outer diameter and length of the balloon portion 22 are determined according to the inner volume of the balloon portion 22 that greatly influences the assisting effect on the cardiac function, the inner diameter of the arterial blood vessel, and the like. The inner volume of the balloon part 22 is not particularly limited, but is 20 to 50 cc. The outer diameter of the balloon part 22 is preferably 12 to 16 mm at the time of inflation, and the length is preferably 150 to 250 mm.

  A distal tip portion 25 having a blood circulation hole 23 is attached to the distal end portion of the balloon portion 22 by means such as heat fusion or adhesion. On the inner peripheral side of the tip portion 25, the tip portion of the inner tube 30 is attached by means such as heat fusion or adhesion.

  A distal end portion of the outer tube 24 is connected to the rear end portion of the balloon portion 22. The pressure fluid is introduced and led out into the balloon portion 22 through the pressure fluid passage 29 formed in the outer tube 24, and the balloon portion 22 is inflated and deflated. The connection between the balloon portion 22 and the outer tube 24 is performed by heat fusion or bonding with an adhesive.

  The inner tube 30 extends in the axial direction inside the balloon portion 22 and the outer tube 24, and does not communicate with the pressure fluid communication path 29 formed inside the balloon portion 22 and inside the outer tube 24. A blood conduction path 31 is formed and communicates with a blood pressure measurement port 32 of a branching section 26 described later at the rear end. As will be described later, the inner tube 30 sends the blood pressure taken in the blood circulation hole 23 of the tip portion 25 to the blood pressure measuring port 32 of the branching portion 26 and measures the blood pressure fluctuation therefrom.

  When the balloon catheter 20 is inserted into the artery, the inner tube 30 positioned in the balloon portion 22 is wound around the balloon portion 22 in a deflated state, and the blood conduction path 31 conveniently connects the balloon portion 22 in the artery. It is also used as a lumen through which a guide wire used for insertion into a tube is inserted.

  A branch portion 26 is connected to the rear end portion of the outer tube 24. The branch portion 26 is formed separately from the outer tube 24 and is connected to the outer tube 24 by means such as heat fusion or adhesion. The branch portion 26 includes a first fluid passage 47 in which a pressure fluid communication path 29 in the outer tube 24 and a pressure fluid inlet / outlet port 28 for introducing and deriving pressure fluid into and from the balloon portion 22 are formed. A second passage 45 in which a blood pressure measurement port 32 communicating with the blood conduction path 31 is formed is formed.

  The pressure fluid inlet / outlet port 28 is connected to a pump device (not shown), and the pressure fluid is introduced into and led out from the balloon portion 22 by this pump device. Although it does not specifically limit as a pressure fluid, Helium gas with small viscosity and mass etc. are used so that the balloon part 22 expand | swells and shrinks rapidly according to the drive of a pump apparatus.

  The blood pressure measurement port 32 is connected to a blood pressure measurement device (not shown), and can measure a change in the blood pressure in the artery taken from the blood circulation hole 23 near the tip of the balloon portion 22. Based on the blood pressure fluctuation measured by this blood pressure measuring device, the pump device is controlled in accordance with the heart beat, and the balloon portion 22 is inflated and deflated in a short cycle of 0.4 to 1 second.

  In the present embodiment, as shown in FIGS. 1 and 3, the outer tube 24 and the inner tube 30 have a length L1 that is 50% or more, preferably 70% or more of the total length of the outer tube 24 from the tip of the outer tube 24. It is fixed by the adhesive 35 throughout. By fixing the outer tube 24 and the inner tube 30 in this manner, the flow resistance of the pressure fluid conduction path 29 in the outer tube 24 is lowered, and the responsiveness of the balloon portion 22 is improved. The adhesive 35 used for fixing is not particularly limited, and an adhesive such as a cyanoacrylate adhesive or an epoxy adhesive can be used, and a cyanoacrylate adhesive is particularly preferable.

  In the present embodiment, as shown in FIG. 2, in the distal end portion of the outer tube 24, a notch 52 extending in the circumferential direction of the outer tube 24 at a position away from the distal end opening surface 50 toward the rear end by a predetermined width W1. Is formed. The cut angle θ2 of the cut 52 is not particularly limited, but is preferably substantially the same as an angle θ1 of the tip opening surface 50 described later. Moreover, it is preferable that the notch 52 is formed in the position which left | separated predetermined width W1 to the axial direction from the front-most corner | angular part in the front end opening surface 50. FIG.

The depth D1 of the notch 52 in the direction perpendicular to the longitudinal axis of the outer tube 24 is preferably not more than the outer diameter D2 of the inner tube 30, and is particularly 55 to 90% of the outer diameter D2. preferable. If the depth D1 is too small, it becomes difficult to form an engagement hole 56 (see FIG. 6) for inserting the inner tube 30 described later. If the depth D1 is too large, the outer tube 24 and the inner tube 30 are not formed. There is a risk that the fixation will be insufficient.

  The predetermined width W1 is not particularly limited, but is preferably 1 to 3 mm. If the width W1 is too small, the inner tube 30 may not be firmly fixed. If the width W1 is too large, the width of the cut piece 54 formed by the cut 52 will increase, and the cut piece 54 will open at the front end. There is a possibility that the responsiveness of the balloon portion 22 may deteriorate due to entering the entrance / exit of the pressure fluid communication path 29 on the surface 50.

  As shown in FIGS. 2, 5, and 6, a notch piece 54, which is a part of the tube wall of the outer tube 24 located between the notch 52 and the tip opening surface 50, is formed inside the outer tube 24. An engagement hole 56 that can be inserted through the inner tube 30 is formed. Then, by inserting the inner tube 30 into the engagement hole 56, the inner tube 30 is fixed to the outer tube 24 at the portion.

  In the balloon catheter 20 of the present embodiment, the inner tube 30 is fixed to the inner wall of the outer tube 24 by inserting the inner tube 30 through the engagement hole 56. It is difficult to peel off from the outer tube 24. In addition, since the fixing means can be configured only by providing a notch at the distal end portion of the outer tube without inserting another member, the distal end opening surface 50 in the outer tube 24 can be widened, and the balloon The responsiveness of the part 22 does not deteriorate. Furthermore, since the engagement hole 56 is formed only by forming the cut 52 and pushing the cut 54, the operation is simple.

  In the present embodiment, as shown in FIGS. 1 and 2, the distal end opening surface 50 of the outer tube 24 is the longitudinal length of the outer tube 24 at the distal end of the outer tube 24 where the rear end of the balloon portion 22 is joined to the outer periphery. An acute angle is formed with respect to the axis. In FIG. 2, the angle θ1 of the distal end opening surface 50 with respect to the longitudinal axis of the outer tube 24 is preferably 20 to 80 degrees, and more preferably 35 to 50 degrees. If the angle θ1 is too small, the distal end opening surface 50 may enter the inside of the balloon portion 22 so that the inflation / deflation operation of the balloon portion 22 may be hindered. If the angle θ1 is too large, the cut piece 54 enters the entrance / exit of the pressure fluid communication path 29 in the tip opening surface 50, and the responsiveness of the balloon portion 22 may be deteriorated.

  Further, in the balloon catheter 20 of the present embodiment, the cut piece 54 is positioned so as to protrude from the distal end opening surface 50 of the outer tube 24 to the distal end side, and thus the engagement hole 56 is formed. However, the entrance / exit of the pressure fluid communication path 29 in the front end opening surface 50 of the outer tube 24 is not narrowed, and the flow path resistance can be reduced. As a result, the responsiveness of the balloon part 22 is improved.

  The outer diameter D2 of the inner tube 30 is not particularly limited, but is preferably 0.5 to 2 mm, and preferably 30 to 60% of the inner diameter D0 of the outer tube 24. In this embodiment, the outer diameter D2 of the inner tube 30 is substantially the same along the axial direction. The inner tube 30 is made of, for example, a synthetic resin tube such as polyurethane, polyvinyl chloride, polyethylene, nylon, polyetheretherketone, a nickel titanium alloy thin tube, a stainless steel thin tube, or the like. Further, when the inner tube 30 is composed of a synthetic resin tube, a stainless steel wire or the like may be embedded.

  The outer tube 24 is not particularly limited, but is composed of a synthetic resin such as polyurethane, polyvinyl chloride, polyethylene terephthalate, or polyamide, and may be embedded with a stainless steel wire or the like. The inner diameter D0 and the wall thickness of the outer tube 24 are not particularly limited, but the inner diameter D0 is preferably 1.5 to 4.0 mm, and the wall thickness is preferably 0.05 to 0.4 mm. The length of the outer tube 24 is preferably 300 to 800 mm.

  In order to form the cut 52 at the distal end portion of the outer tube 24, as shown in FIG. 4, after cutting the distal end of the outer tube 24 obliquely, the distal end opening surface 50 is brought into contact with the slide table 60, What is necessary is just to move to the front-end | tip direction of the cutting blade 66. FIG. The cutting blade 66 is held by the top plate 62 so as to be positioned at a predetermined height W1 (same as the predetermined width W1) from the surface of the slide table 60. A recess 64 is formed at the tip of the top plate 62, and the tip of the cutting blade 66 protrudes into the recess 64 with a predetermined length. The protruding length of the cutting blade 66 defines the depth of the cut 52.

  After that, as shown in FIGS. 5 and 6, the cut piece 54 is pushed into the outer tube 24 to be turned back, and the cut piece 54 is protruded from the distal end opening surface 50 toward the distal end side. Make a habit. In order to set the engagement hole 56, a metal mandrel 70 having the same outer diameter as the inner tube 30 or slightly smaller than the outer diameter is passed through the engagement hole 56. For example, a forming iron heated to about 90 ° C. is pressed from the outside of the insert piece 54. As a result, the shape of the engagement hole 56 is maintained.

  Thereafter, the mandrel 70 is taken out from the engagement hole 56 and, instead, the inner tube 30 is inserted. Next, as shown in FIGS. 1 and 3, the inner tube 30 is bonded to the inner wall of the outer tube 24 by the adhesive 35 over a predetermined length L <b> 1 from the tip of the outer tube 24. In addition, it is preferable to apply an adhesive so as to surround the cut piece 54 and the inner tube 30 located in the vicinity thereof and solidify it. By applying the adhesive in this manner, the cut piece 54 is prevented from being broken.

  Thereafter, the distal end portion of the balloon portion 22 is joined to the distal end portion of the inner tube 30 by adhesion or the like, and the rear end portion of the balloon portion 22 is joined to the outer periphery of the distal end portion of the outer tube 24 by fusion or the like. Further, the branch portion 26 is connected to the rear end portion of the outer tube 24 by adhesion or the like.

Second Embodiment In the present embodiment, as shown in FIG. 2, the outer diameter D3 of the inner tube 30a positioned on the front end side with respect to the cut piece 54 is changed to the inner tube positioned on the rear end side with respect to the cut piece 54. It is larger than 30 outer diameter D2. In other words, the outer diameter D2 of the inner tube 30 positioned on the rear end side of the cut piece 54 is smaller than the outer diameter D3 of the inner tube 30a positioned on the front end side of the cut piece 54. . Other configurations are the same as those of the first embodiment, and a detailed description thereof will be omitted.

  The inner diameter of the blood conduction path 31 formed in the inner tube 30 is preferably the same in the inner tube 30a on the front end side and the inner tube 30 on the rear end side, but it is not necessarily the same. When the inner diameter of the blood conduction path 31 is the same between the inner tube 30a on the front end side and the inner tube 30 on the rear end side, the thickness of the inner tube 30 on the rear end side may be reduced.

  The outer diameter D3 of the inner tube 30a on the front end side is preferably 1 to 30% larger than the outer diameter D2 of the inner tube 30 on the rear end side. With such a configuration, even when the balloon portion 22 is about to be pushed back into the bloodstream, the inner tube 30a having a large outer diameter is caught by the cut piece 54, and the balloon portion 22 is prevented from being pushed back further. The

  Further, in the present embodiment, the outer diameter of the inner tube 30a on the distal end side is set to the same level as the inner tube of the conventional balloon catheter in the balloon portion 22, and the rear end side located inside the outer tube 24 is set. By setting the outer diameter of the inner tube 30 to be smaller than the conventional one, the following operational effects can be obtained. That is, the inner tube 30 positioned inside the balloon portion 22 is given sufficient rigidity to support the balloon portion 22 while increasing the cross-sectional area of the pressure fluid conduction path 29, and the responsiveness of the balloon portion 22 is increased. Can be improved. Since the outer tube 24 itself has a certain degree of rigidity inside the outer tube 24, no problem occurs even if the rigidity of the inner tube 30 is reduced.

Other Embodiments The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

  For example, the shape of the tip opening surface 50 shown in the figure and the shape of the notch 52 are not limited to a straight line, and may be a curved line.

  Further, it is possible to fix the outer tube 24 and the inner tube 30 with only the engagement hole 56 without fixing them with the adhesive 35.

  The use of the balloon catheter of the present invention requires that the outer tube and the inner tube be firmly fixed at the distal end of the outer tube, and that the distal end surface of the outer tube must be widened. Although it is preferable to use it as a balloon catheter, it is not limited to this. For example, the balloon catheter of the present invention can be used as a PTCA catheter, a PTA catheter, or the like.

FIG. 1 is a schematic cross-sectional view of a balloon catheter according to an embodiment of the present invention. FIG. 2 is an enlarged view showing details of an engaging portion between the outer tube and the inner tube shown in FIG. 3 is a schematic perspective view showing a fixed state of the outer tube and the inner tube shown in FIG. FIG. 4 is a schematic view showing a process for making a cut at the tip of the outer tube. FIG. 5 is a schematic view showing a step subsequent to FIG. FIG. 6 is a cross-sectional view of a principal part taken along line VI-VI in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Balloon catheter 22 ... Balloon part 24 ... Outer pipe 29 ... Pressure fluid conduction path 30 ... Inner pipe 31 ... Blood conduction path 50 ... Tip opening surface 52 ... Cut 54 ... Cut piece 56 ... Engagement hole

Claims (5)

A balloon portion that can be inflated and deflated, and
An outer tube having a tip connected to a rear end of the balloon so as to introduce and lead a pressure fluid into and out of the balloon;
A balloon catheter having a distal end portion of the balloon portion connected and an inner tube extending in the axial direction inside the balloon portion and the outer tube,
In the distal end portion of the outer tube where the rear end portion of the balloon portion is joined to the outer periphery, the distal end opening surface of the outer tube forms an acute angle with respect to the longitudinal axis of the outer tube,
In the front end portion of the outer tube, a notch extending in the circumferential direction of the outer tube is formed at a position away from the front end opening surface of the outer tube toward the rear end by a predetermined width,
A notch piece, which is a part of the tube wall of the outer tube located between the notch and the opening surface of the distal end, is pushed toward the inside of the outer tube, so that it is directed toward the inside of the outer tube. An engagement hole is formed between a part of the outer wall of the outer tube pushed in and the inner wall of the outer tube, and the inner tube can be inserted therethrough.
The balloon catheter , wherein the inner tube and the outer tube are engaged by inserting the inner tube through the engagement hole. The balloon catheter according to claim 1, wherein the cutting piece is positioned so as to protrude from a distal end opening surface of the outer tube to a distal end side to form the engagement hole. Wherein the outer diameter of the inner tube positioned at the front end side of the cut pieces, either a major claim 1 or 2 than the outer diameter of the inner tube positioned at the rear end side of the cut piece Balloon catheter. The balloon catheter according to any one of claims 1 to 3 , which is used for an intra-aortic balloon pumping method. The angle θ1 of the tip opening surface with respect to the longitudinal axis of the outer tube is 35 to 50 degrees,
The incision angle θ2 with respect to the longitudinal axis of the outer tube is substantially the same as the angle θ1,
The incision is formed at a position 1 to 3 mm away from the most advanced corner in the tip opening surface in the axial direction,
  The balloon catheter according to any one of claims 1 to 4, wherein a depth D1 of the cut in a direction perpendicular to the longitudinal axis of the outer tube is 55 to 90% of an outer diameter D2 of the inner tube.

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