JP2005287585A - Intra-aortic balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intra-aortic balloon catheter in which the flow path resistance of a pressure fluid conducting path is reduced without increasing burdens on a patient, a balloon part is expanded or contracted with excellent responsiveness and the excellent responsiveness is maintained even when driven for a long period of time. <P>SOLUTION: The intra-aortic balloon catheter 20 is provided with the balloon part 22 inserted inside the aorta and expanded and contracted so as to perform the action of assisting a heart function, an outer tube 24 connected to the rear end part of the balloon part 22 so as to introduce and lead out a pressure fluid to/from the inside of the balloon part 22, and an inner tube 30 connected to the tip part of the balloon part 22 and extended in an axial direction inside the balloon part 22 and the outer tube 24. Over the length L1 which is 50% or more of the entire length from the tip part of the outer tube 24, the inner tube 30 is adhered or fused on the inner wall of the outer tube 24. At the tip part of the outer tube 24, the inner tube 30 is engaged with the inner wall of the outer tube 24 by a cut piece 54. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intra-aortic balloon catheter used for intra-aortic balloon pumping, which is a treatment method for acute heart failure, for example. .

  A balloon pumping method (IABP) is used as an auxiliary circulation method for assisting cardiac function by inserting a balloon catheter into the aorta and inflating and deflating the balloon in accordance with the heartbeat for the treatment of cardiac function deterioration. Law) is known.

  Various performances are required for an intra-aortic balloon catheter used in the IABP method. Among them, it has a thin outer diameter for reasons such as preventing lower limb ischemia and reducing the burden on the patient. It has been demanded. Further, in recent years, in order to further reduce the burden on the patient, it has been studied to insert a catheter from the brachial artery instead of the conventional femoral artery, and an intra-aortic balloon catheter having a thinner outer diameter is required. Yes.

  However, simply thinning the catheter increases the flow resistance of the flow path through which the fluid for inflating and deflating the balloon increases, and the time required to inflate and deflate the balloon becomes longer (the responsiveness becomes worse). It becomes difficult to inflate and deflate the balloon according to the heartbeat. Therefore, in order to reduce the diameter of the intra-aortic balloon catheter, it is necessary to improve responsiveness.

  As a technique for improving the responsiveness of this intra-aortic balloon catheter, a technique is known in which the inner tube is fixed to the inner wall of the outer tube by means such as adhesion or fusion (Patent Document 1). According to this method, an increase in flow resistance caused by the inner pipe being bent in the outer pipe is prevented, and as a result, the responsiveness is improved.

  However, when the intra-aortic balloon catheter to which the above method is applied is driven for a long time, the responsiveness may gradually deteriorate, and in the worst case, the balloon is inflated and deflated according to the heart beat. May not be able to be performed, and the assist effect of the cardiac function may be significantly reduced.

  By the way, in Patent Document 2, for the purpose of preventing the phenomenon that the catheter becomes difficult to insert into the body due to the relative movement of the inner tube and the outer tube, another member for engagement is provided inside the distal end side of the outer tube. Thus, an intra-aortic balloon catheter is described in which the inner tube and the outer tube are fixed in the vicinity of the distal end of the outer tube.

  However, in the method of fixing the outer tube and the inner tube only near the distal end of the outer tube as in the balloon catheter of Patent Document 2, the inner tube is not fixed to the outer tube because most of the inner tube is not fixed to the outer tube. In some cases, the responsiveness deteriorates due to winding in the tube.

In addition, in the intra-aortic balloon catheter in which the inner tube and the outer tube are fixed over most of the entire length of the outer tube by adhesion or fusion as described in Patent Document 1, the inner tube is sufficiently bonded by adhesion or fusion. Since relative movement between the tube and the outer tube is prevented, it has been considered that there is no need to provide a separate member for engagement as described in Patent Document 2.
JP-A-5-123403 JP 2003-701

  The present invention has been made in view of such circumstances, and without increasing the burden on the patient, the flow resistance of the pressure fluid communication path is reduced, the balloon portion is inflated and deflated with good responsiveness, and driven for a long time. Another object of the present invention is to provide an intra-aortic balloon catheter that maintains excellent responsiveness.

  As a result of intensive studies to achieve the above object, the present inventors have found that, in an intra-aortic balloon catheter in which the outer tube and the inner tube are fixed by adhesion or fusion, when the balloon is driven for a long time, the outer tube and the inner tube are It was found that the tube gradually peeled off from the vicinity of the tip of the outer tube, resulting in deterioration of responsiveness over time. Then, the outer tube and the inner tube of the balloon catheter in the aorta are fixed by adhesion or fusion, and further, the outer tube and the inner tube are fixed by engagement in the vicinity of the distal end of the outer tube. Further, it was found that the inner tube and the outer tube are prevented from being peeled off, and as a result, the deterioration of responsiveness with time is prevented, and the present invention has been completed based on this finding.

Thus, the intra-aortic balloon catheter according to the present invention is
A balloon that is inserted into the aorta and inflated and deflated to assist in cardiac function;
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;
An intra-aortic balloon catheter having a distal end portion of the balloon portion connected and an inner tube extending in an axial direction inside the balloon portion and the outer tube,
The inner tube is bonded or fused to the inner wall of the outer tube over a length of 50% or more of the total length from the tip of the outer tube,
The inner tube is engaged with the inner wall of the outer tube by engaging means at the tip of the outer tube.

Preferably, the front end portion of the outer tube is formed with a notch extending in the circumferential direction of the outer tube at a position separated from the front end opening surface of the outer tube by a predetermined width toward the rear end.
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 engaged with the inner wall of the outer tube by being inserted into 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 located on the front end side with respect to the engaging means is larger than the outer diameter of the inner pipe located on the rear end side with respect to the engaging means.

  According to the present invention, without increasing the burden on the patient, the flow resistance of the pressure fluid communication path is reduced, the balloon portion is inflated and deflated with good responsiveness, and excellent responsiveness is achieved even when driven for a long time. A maintained intra-aortic balloon catheter is provided.

  In the intra-aortic balloon catheter of the present invention, the outer tube and the inner tube are fixed by adhesion or fusion over a length of 50% or more of the total length of the outer tube. The tube and the inner tube are fixed by engagement.

  In the intra-aortic balloon catheter of the present invention, the outer tube and the inner tube are fixed over a length of 50% or more of the total length of the outer tube, so that the inner tube does not bend in the outer tube, and the pressure fluid An increase in flow path resistance in the circulating outer pipe (pressure fluid communication path) is prevented. As a result, the responsiveness of the balloon part is improved.

  The outer tube and the inner tube are more preferably fixed over a length of 70% or more of the entire length of the outer tube, and more preferably are fixed over the entire length of the outer tube.

  The fixing is not limited as long as it can substantially prevent the inner tube from bending in the outer tube, and does not necessarily need to be continuously fixed over the entire range of the predetermined length. It may be fixed at intervals.

  Adhesion between the outer tube and the inner tube over 50% or more of the total length of the outer tube is performed by adhesion or fusion. By fixing by adhesion or fusion, the materials of the outer tube and the inner tube can be selected relatively freely, and the flow resistance in the outer tube is hardly increased. Among these, from the viewpoint of workability and a higher degree of freedom in material selection, it is preferable to perform fixing by adhesion. On the other hand, when this fixation is performed by engagement, the flow resistance in the outer tube is increased by the engagement means, and the responsiveness of the balloon portion may be deteriorated. In addition, when the inner tube and the outer tube are integrally formed, the range of material selection for the inner tube and the outer tube is narrowed, and it is difficult to select a preferable material for each.

  The type of adhesive used when fixing is performed by adhesion 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.

  When fixing is performed by fusion, techniques such as heat fusion, solvent fusion, ultrasonic fusion, and high frequency fusion can be employed.

  In the intra-aortic balloon catheter of the present invention, the outer tube and the inner tube are fixed by adhesion or fusion over a length of 50% or more of the total length of the outer tube, and further, at the distal end of the outer tube, It is fixed by engagement. Due to the fixation by this engagement, a phenomenon in which the outer tube and the inner tube fixed by adhesion or fusion are separated by long-time driving of the intra-aortic balloon catheter and the responsiveness deteriorates with time is prevented.

  In addition, since it is sufficient that the fixing by the engagement is performed in a very small range at the distal end portion of the outer tube, an increase in flow resistance in the outer tube by the engaging means can be minimized.

  The engaging means used for the above engagement may be formed by processing the outer tube or the inner tube itself, or may be formed as a separate member from the inner tube and the outer tube. From the viewpoint of avoidance, it is preferable to form the engaging means by processing the outer tube or the inner tube itself, and it is particularly preferable to process the outer tube.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a schematic cross-sectional view of an intra-aortic 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.

Intra-aortic balloon catheter 20 according to an embodiment of the present invention shown in the first embodiment <br/> Figure 1 is a balloon catheter for use in the intra-aortic balloon pumping method, expand and contract in accordance with the pulsation of the heart It has a balloon part 22. 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 internal 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 when inflated, 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. Engagement may 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 engagement of the inner tube 30 may be insufficient. If it is too large, the width of the cut piece 54 formed by the cut 52 will be large, and the cut piece 54 will be at the tip. There is a possibility that the responsiveness of the balloon portion 22 is deteriorated by entering the entrance / exit of the pressure fluid communication path 29 in the opening 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. Thus, the engagement hole 56 into which the inner tube 30 can be inserted is formed. Then, by inserting the inner tube 30 into the engagement hole 56, the cut piece 54 functions as an engagement means, and the inner tube 30 is engaged with the inner wall of the outer tube 24 in this 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.

  In the balloon catheter according to this embodiment, the outer tube 24 and the inner tube 30 are fixed over a predetermined length L1, and the inner tube 30 is engaged with the cut piece 54 at the distal end portion of the outer tube 24. It is. By this engagement, even when the intra-aortic balloon catheter 20 is driven for a long time, the inner tube 30 fixed by adhesion is not peeled off from the outer tube 24, and the phenomenon that the responsiveness deteriorates with time is prevented.

In the present embodiment, the engagement means is formed simply by forming the cut 52 at the distal end portion of the outer tube 24 and pushing the resulting cut piece 54. Can be improved and the engagement means can be prevented from falling off.
Second Embodiment In the present embodiment, as shown in FIG. 2, the outer diameter D <b> 3 of the inner tube 30 a located on the front end side with respect to the cut piece 54 is set to the rear end side with respect to the cut piece 54. It is larger than the outer diameter D2 of the positioned inner tube 30. 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. In the present invention, the engaging means is not limited to the cut piece 54 shown in the figure, and may have other structures. For example, a tube member having a recessed portion on the outer peripheral portion along the axial direction may be inserted into the distal end portion of the outer tube 24 so that the inner tube 30 fits in the recessed portion, and the engagement may be performed.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

Example 1
A balloon catheter 20 shown in FIGS. 1 to 3 was manufactured. In FIG. 2, the inner tube 30 has an outer diameter D2 of 1.10 mm, an inner diameter of 0.84 mm, and the same outer diameter along the axial direction. The outer diameter of the outer tube 24 was 2.70 mm, the inner diameter D0 was 2.40 mm, and the total length was 600 mm. The angle θ1 of the tip opening surface 50 of the tube 24 was 40 degrees. Further, the angle θ2 of the cut 52 was the same as the angle θ1, and the depth D1 of the cut 52 was 0.6 mm. The width of the cut piece 54 was 1.0 mm.

  The material constituting the outer tube 24 is polyurethane, the material constituting the inner tube 30 is polyetheretherketone, and the material of the balloon membrane constituting the cylindrical balloon portion 22 is polyurethane. The internal volume was 40 cc. The inner tube 30 is passed through the engagement hole 56 of the cut piece 54, and extends from the cut piece 54 to the rear end side over a predetermined length L1 = 500 mm (83% of the total length of the outer tube 24). The agent was fixed on the inner wall of the outer tube 24 in a substantially straight line.

  The experimental results of examining the responsiveness of inflation / deflation of the balloon portion 22 using the balloon catheter 20 under the following conditions are shown below. Helium was used as the pressure fluid flowing through the pressure fluid passage 29.

  The outer tube of the balloon catheter is bent three times in a semicircle continuously with a curvature of about 5 cm in radius, and helium is introduced and led out through the inner portion of the outer tube (pressure fluid communication path). The time TI from the minimum contracted state to the maximum expansion and the time TD from the maximum expansion to the minimum contraction were examined. It was confirmed that TI + TD was 203 milliseconds at the initial stage of driving, and 204 milliseconds after 14 days of continuous driving, with almost no change, with an average value measured five times for each. Note that the smaller the TI + TD, the better the response.

Example 2
A balloon catheter was manufactured in the same manner as in Example 1 except that the angle θ1 of the tip opening surface 50 and the angle θ2 of the notch 52 shown in FIG. TI + TD was 221 milliseconds at the beginning of driving, and 222 milliseconds after 14 days of continuous driving, which was confirmed to be almost unchanged.

Comparative Example 1
A balloon catheter was manufactured in the same manner as in Example 1 except that the notch 52 was not formed and the inner tube was not fixed by the engagement hole 56, and a similar experiment was performed.

  TI + TD was 202 milliseconds at the initial stage of driving, and 232 milliseconds after 14 days of continuous driving, and it was confirmed that the responsiveness deteriorated with time.

Comparative Example 2
A balloon catheter was manufactured in the same manner as in Example 1 except that the inner tube was not bonded to the inner wall of the outer tube with an adhesive, and a similar experiment was performed. TI + TD was 252 milliseconds at the beginning of driving, and then 254 milliseconds after 14 days of continuous driving, and there was almost no deterioration in responsiveness over time, but compared to Examples 1 and 2. It was confirmed that the response was poor.

FIG. 1 is a schematic cross-sectional view of an intra-aortic 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 in aorta 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 (engagement means)
56 ... engagement hole

Claims (5)

A balloon that is inserted into the aorta and inflated and deflated to assist in cardiac function;
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;
An intra-aortic 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,
The inner tube is bonded or fused to the inner wall of the outer tube over a length of 50% or more of the total length from the tip of the outer tube,
An intra-aortic balloon catheter characterized in that the inner tube is engaged with the inner wall of the outer tube by engaging means at the distal end 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 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 intra-aortic balloon catheter according to claim 1, wherein the inner tube is engaged with the inner wall of the outer tube by being inserted into the engagement hole. The intra-aortic balloon catheter according to claim 2, wherein a distal end opening surface of the outer tube forms an acute angle with respect to a longitudinal axis of the outer tube. The intra-aortic balloon catheter according to claim 3, wherein the incision piece is positioned so as to protrude from the distal end opening surface of the outer tube toward the distal end side to form the engagement hole. 5. The outer diameter of the inner tube located on the distal end side with respect to the engagement means is larger than the outer diameter of the inner tube located on the rear end side with respect to the engagement means. Intra-aortic balloon catheter.

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