JP2008264119A - Catheter with pressing property - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter having such pressing properties as can efficiently transmit the force applied to the proximal end side of the catheter to the distal end side of the catheter or distal end without complicating the manufacturing process or increasing the manufacturing cost, and without reducing the operability when the catheter is inserted along a guide wire from outside of a living body. <P>SOLUTION: The catheter comprises at least a distal end shaft composed of a resin tube, a rear end shaft with higher rigidity than the distal end shaft, and a guide wire lumen. The guide wire lumen has a distal end opening part formed at the most distal end of the catheter and a rear end opening part formed on the way of the distal end shaft. The distal end of the rear end shaft and the rear end of the distal end shaft are jointed to each other, and the cross-sectional area 14 of the clearance of the guide wire 13 to be used together with the guide wire lumen is 0.04-0.12 mm<SP>2</SP>. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a catheter used for medical applications, and more specifically, percutaneous angioplasty (PTA: Percutaneous Transgenic Angioplasty, PTCA: Percutaneous Transluminal Coronary Angioplasty). ), A catheter for penetrating a stenosis, an injection catheter capable of administering a therapeutic substance to a local site, and the like.

  2. Description of the Related Art Conventionally, percutaneous angioplasty is widely used for the purpose of expanding or treating a stenosis or occlusion in a blood vessel lumen and restoring or improving blood flow in a coronary artery or a peripheral blood vessel. A balloon catheter used for percutaneous angioplasty is formed by joining a balloon that can be inflated and deflated by adjusting internal pressure to the tip of a shaft, and a guide wire is inserted into the shaft. A structure in which a cavity (guide wire lumen) and a lumen (inflation lumen) for supplying a pressure fluid for adjusting balloon internal pressure are provided along the longitudinal direction of the shaft.

  A general surgical example of PTCA using such a balloon catheter is as follows. First, a guide catheter is inserted from a puncture site such as the femoral artery, brachial artery, and radial artery, and the distal end thereof is disposed at the entrance of the coronary artery via the aorta. Next, the guide wire inserted through the guide wire lumen is advanced beyond the stenotic site of the coronary artery, and a balloon catheter is inserted along the guide wire so that the balloon matches the stenosis. The diameter of a guide wire used in general PTCA is 0.014 inch. Next, using a device such as an inflator, a pressure fluid is supplied to the balloon via the inflation lumen, and the balloon is inflated to expand the stenosis. After dilatation treatment of the stenosis, PTCA is terminated by retracting the balloon under reduced pressure and removing it from the body.

  The catheter described above has a structure in which the distal end side shaft and the rear end side shaft are joined, and the adapter member for holding the catheter is connected to the rear end of the rear end side shaft. The catheter is roughly classified into two types according to the length of the guide wire lumen. Is done. Hereinafter, a balloon catheter in which a balloon is connected to the distal end side of the distal shaft and the adapter member has a port for supplying a pressure fluid for adjusting the internal pressure of the balloon to the inflation lumen will be described as an example.

  As shown in FIG. 1, the guide wire lumen is provided over the entire length of the catheter as shown in FIG. 1, and the adapter member is provided with the opening on the rear end side of the guide wire lumen and the opening of the inflation lumen, and simultaneously controls the axial flexibility. An over-the-wire type in which a strain relief is provided on the adapter member, and a rear end side opening of the guide wire lumen is provided on the rear end side of the front end portion of the balloon or the front end portion of the balloon ( OTW type). The other is a high-speed exchange type (RX type) in which the guide wire lumen exists only on the distal end side of the balloon catheter as shown in FIG. 2, and the rear end side opening of the guide wire lumen is provided in the middle of the distal end side shaft. ). Since the OTW type has a guide wire lumen over the entire length of the balloon catheter, it is often used for lesions in which it is difficult to pass the guide wire. However, the operation of removing the balloon catheter while the guide wire is left in the lesion is difficult. There is a problem that is complicated. That is, in the OTW type, in order to remove the balloon catheter while the guide wire is left in the lesioned area, a special device or operation such as attachment of a replacement extension wire is required.

  On the other hand, in the RX type, since the guide wire lumen exists only on the distal side of the balloon catheter, the balloon catheter can be easily removed, replaced, and reinserted while the guide wire remains in the lesioned portion, and the operability is improved. Not only is it very good, but also the operation time can be shortened, and the number of devices used can be reduced.

  The structure of the catheter is roughly classified into two according to the shaft structure where the guide wire lumen exists. As shown in FIG. 4, one is an outer shaft disposed so as to coaxially surround the inner shaft and the inner shaft, and a guide wire lumen formed from a lumen of the inner shaft and the inner shaft and the outer shaft. It is a coaxial type (co-axial type) having an inflation lumen formed in an annular shape between shafts. The other is a biaxial type (bi-axial type) structure in which a guide wire lumen and an inflation lumen are arranged in parallel as shown in a cross-sectional shape in FIG.

  In the case of an OTW type catheter, a coaxial type or biaxial type structure is generally provided over the entire length. On the other hand, in the case of the RX type catheter, the distal shaft of the portion where the guide wire lumen exists can have a coaxial type or biaxial type structure.

  In the above, a balloon catheter having a balloon provided on the distal end side of the distal shaft is illustrated, but the characteristics of the OTW type and the RX type are not limited to the balloon catheter, but a penetration catheter for penetrating a stenosis and a therapeutic substance administration This is common to other infusion catheters and other catheters. The present invention relates to such an RX-type catheter.

  One of the performances of such a catheter is pressability. Here, pressability means how accurately the force applied to the catheter proximal part is transmitted to the catheter tip, and is a performance that is more important than the strength of the pressing force in the treatment of important parts such as coronary arteries. It is. On the other hand, the pressing force means a force applied to the distal end portion of the catheter when the proximal portion of the catheter is pushed, and is a performance necessary for the catheter to pass through the lesioned portion. Accordingly, various techniques have been disclosed in order to further improve the pressability.

  In patent document 1, it is an elongate catheter which consists of an inner tubular member, an outer tubular member, and an expansion balloon, Comprising: A 2nd lumen | bore is formed between an inner tubular member and an outer tubular member, and the said expansion balloon is a 2nd lumen | bore At least 30% of the inner circumferential surface of the outer tubular member and bonded to the outer surface of the inner tubular member. A catheter having an inner peripheral surface is disclosed.

  According to this prior art, by adhering the longitudinal portion of the outer tubular member to the outer surface of the inner tubular member, the outer diameter of the catheter body can be reduced at least in one direction in this region, and the diameter can be reduced. Is done. Furthermore, since the adhesion part of an inner tubular member and an outer tubular member mutually supports, the pressability of a catheter is improved. However, since the inner tubular member and the outer tubular member are bonded to each other at the bonded longitudinal portion, the flexibility is lowered, and the operability when the bonded longitudinal portion passes through the bent blood vessel is not good. Further, in the state in which the bonding longitudinal portion is bent, the second lumen included in the bonding longitudinal portion is likely to be deformed, and the expansion / contraction response of the dilatation balloon is low.

  Further, in Patent Document 2, a main shaft constituted by a metal tube, a balloon, a plastic shaft portion between the main shaft and the balloon, and attached to the main shaft, extends in the plastic shaft portion in the proximal direction and is not harder than the main shaft portion. An intravascular catheter is disclosed that includes an intermediate member, a guidewire lumen, and wherein the guidewire inlet is spaced proximally from the proximal end of the main shaft portion.

  In this prior art, a catheter with improved propulsiveness (pressability) and followability has been realized, and the operability when inserting the catheter from outside the body along the guide wire has been improved. There is a problem. In other words, a process such as brazing or laser bonding for attaching an intermediate member that is not hard compared to the main shaft part to the main shaft is necessary, and there are problems such as an increase in manufacturing cost due to large-scale installation of equipment and a complicated process. .

  Patent Document 3 discloses an expansion catheter characterized by having a stylet that increases the compressive strength and axial force transmission (pushability) of the catheter shaft.

In this prior art, the transmission of the axial force (pressability) is improved by the presence of the stylet, and at the same time, the operability when inserting the catheter from outside the body along the guide wire is improved. Since the base end of the let ends with a hub member including the base end portion of the catheter shaft, in the case of a balloon catheter, the stylet is present in the most part of the inflation lumen, and the response of expansion / contraction of the balloon Poor nature is a problem. In addition, in the case of an infusion catheter, the stylet is present in the majority of the infusion lumen (the lumen for injecting the therapeutic substance), and there is a problem that the operability at the time of injecting the therapeutic substance is low.
Japanese Patent No. 3399556 Japanese Patent Publication No. 6-507105 Japanese National Patent Publication No. 9-503411

  Therefore, in view of the above problems, the present invention intends to solve the problem that the operability when the catheter is inserted from outside the body along the guide wire without complicating the process and increasing the manufacturing cost is reduced. In the case of a balloon catheter, there is a pressing property capable of efficiently transmitting the force applied to the rear end side of the catheter to the distal end side or the distal end of the catheter without impairing the response of expansion / contraction of the balloon. It is to realize a catheter.

As a result of intensive studies to solve the above problems, a distal end side shaft made of a resin tube, a rear end side shaft having higher rigidity than the distal end side shaft, a guide wire can be accommodated therein, and the distal end side A catheter having at least a guide wire lumen having an opening and a rear end opening, wherein the guide wire lumen extends toward the distal end of the catheter and forms the distal opening on the most distal portion of the catheter. Simultaneously, the rear end side opening is formed in the middle of the front end side shaft, the front end portion of the rear end side shaft and the rear end portion of the front end side shaft are joined, and the guide wire to be used in combination with the guide wire lumen wherein the clearance cross-sectional area of a 0.04～0.12Mm ² throughout the length direction unillustrated guide wire lumen This has led to the invention of the catheters. As shown in FIG. 8, the clearance cross-sectional area of the guide wire to be used together with the guide wire lumen represents the difference between the cross-sectional area of the guide wire to be used together with the lumen cross-sectional area of the guide wire lumen. By setting the clearance cross-sectional area of the inner shaft and the guide wire within the above range, the guide wire can be prevented from being bent, the pushability of the catheter can be improved, and the force applied to the proximal side of the catheter can be applied to the distal side or far side of the catheter. It can be transmitted efficiently to the end.

  Here, in particular, the outer diameter of the guide wire used in the catheter is preferably 0.010 inch. The diameter of the guide wire used in general PTCA is 0.014 inch, and it is conceivable to increase the diameter of the catheter or the guide wire to be used in order to improve the pressing force. By reducing the size, the diameter of the entire catheter can be reduced. By reducing the diameter of the catheter, the resistance load when the catheter enters along the guide wire is also reduced, and the force applied to the proximal side of the catheter is further increased without reducing the guide wire sliding performance of the catheter. It is thought that it is efficiently transmitted to the distal side or the distal end.

  It also improves operability when pushing the catheter from outside the body along the guide wire, efficiently transmits the force applied to the catheter to the distal end, prevents kinking of the catheter, etc. For this purpose, a core wire may be provided in the catheter. The core wire may be disposed in any part of the catheter, but the rear end side (hereinafter referred to as the front end side shaft rear end side) of the front end side shaft of the guide wire lumen is the front end side. It is disposed in the catheter so that it is harder than the rear end side opening of the guide wire lumen of the shaft (hereinafter referred to as the front end side of the front end side shaft) and softer than the rear end side shaft. Preferably it is.

  The catheter according to the present invention may be any of a balloon catheter, a penetration catheter for penetrating a body cavity constriction, and an infusion catheter capable of administering a therapeutic substance to a local site of the body cavity. In the case of a balloon catheter, when taking into account balloon expansion / deflation responsiveness, an inner shaft that forms a guide wire lumen and an outer shaft disposed so as to surround the inner shaft coaxially are provided. A coaxial type (co-axial type) in which an inflation lumen is formed in a ring shape between them is preferable, but a biaxial type (bi-axial type) structure in which a guide wire lumen and an inflation lumen are arranged in parallel may be used. . In the case of the coaxial type, the wall thickness of the inner shaft that forms the guide wire lumen is 0.040 to 0.005 in view of balloon expansion / contraction responsiveness and flexibility required when the catheter enters the body. It is preferable that it is 080 mm.

  According to the present invention, without complicating the process and increasing the manufacturing cost, the balloon can be expanded and expanded in the case of a balloon catheter without reducing the operability when inserting the catheter from outside the body along the guide wire. A catheter having a pressing property capable of efficiently transmitting the force applied to the rear end side of the catheter to the distal end side or the distal end of the catheter without impairing the responsiveness of contraction can be realized.

Hereinafter, various embodiments of a catheter according to the present invention will be described in detail with reference to the drawings as a main example of the case where the catheter is a balloon catheter.
The catheter according to the present invention has a guide wire lumen as shown in FIG. 2 only on the distal end side of the catheter, and a rear end side opening of the guide wire lumen is provided in the middle of the distal end side shaft. This relates to the type (RX type). In consideration of balloon expansion / deflation responsiveness, as shown in FIGS. 3 and 4, the distal end side of the distal end shaft is coaxially double-tube-shaped with an outer tube and an inner tube, and is defined by the inner surface of the inner tube. A co-axial type structure having a second lumen defined by the inner surface of the guide wire lumen and the outer tube and the outer surface of the inner tube is more preferred. However, as shown in FIGS. It may be a bi-axial type structure in which the second lumen is arranged in parallel. Further, other structures do not limit the effects of the invention.

The catheter according to the present invention is characterized in that the clearance cross-sectional area of the guide wire to be used in combination with the guide wire lumen is 0.04 to 0.12 mm ^2. How accurately the applied force is transmitted to the catheter tip) is improved, but is preferably 0.06 to 0.10 mm ² . In this case, the inner diameter of the guide wire lumen and the outer diameter of the guide wire to be used can be selected according to the use site of the catheter. For example, in the case of a balloon catheter for PTCA, the inner diameter of the guide wire lumen is 0.26 mm to 0.40 mm, preferably 0.29 mm to 0.32 mm, and the outer diameter of the guide wire used together is 0.010 inch to 0.014. Inches, preferably 0.010 inches.

In the case of the coaxial type, considering the balloon expansion / contraction response, the wall thickness of the inner shaft forming the guide wire lumen is preferably 0.040 to 0.080 mm, more preferably 0.050 It is preferable that it is 0.070 mm.
The rear end opening of the guide wire lumen exists on the front end side of the rear end side shaft by the length of the rear end side shaft. In this case, in this case, the front end side shaft, that is, the front end side shaft front end side or front end The length of the side shaft rear end side is not particularly limited, and can be selected according to the use site of the catheter. For example, in the case of a balloon catheter for PTCA, the length of the distal end side shaft is 100 mm to 600 mm, preferably 200 mm to 500 mm, and the distal end side shaft distal end length (≈guide wire lumen length) is 50 mm to 450 mm. , Preferably 150 mm to 350 mm. The length of the rear end side of the front shaft is 50 mm to 300 mm, preferably 50 mm to 200 mm. Within the above range, the length of each part can be adjusted according to the use part of the balloon catheter. Also, when the catheter is a penetrating catheter or an infusion catheter, it can be adjusted according to the purpose.

  The material which comprises the said front end side shaft, ie, an inner shaft, and an outer shaft, is not specifically limited. As the inner shaft, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, or the like can be used. Since the lumen of the inner shaft forms a guide wire lumen, it is preferable to use polyethylene, especially high-density polyethylene, considering the slidability of the guide wire, and at least a part of the inner shaft has a multi-layer structure, and the innermost layer is high. More preferably, the density polyethylene and the outermost layer are made of a material that can be melted with the balloon and the outer shaft. Moreover, in order to improve the slidability of the guide wire, a coating of polydimethylsiloxane or the like may be applied to the inner shaft lumen.

  The material of the outer shaft is not particularly limited. That is, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer and the like can be used.

  Similarly, the material of the rear end side shaft is not particularly limited, but the material of the rear end side shaft is preferably substantially equal to or higher in rigidity than the front end side shaft. Furthermore, from the viewpoint of processability, safety to the living body, and the like, a high-rigidity resin material such as a metal such as stainless steel, polyimide, polyamideimide, or polyetheretherketone is preferable. Also, in order to continuously distribute the rigidity in the longitudinal direction of the catheter, the distal end side rigidity of the rear end side shaft is formed by forming a spiral cut, groove, slit, etc. on the front end side of the rear end side shaft. May be lowered as compared with the rear end side of the rear end side shaft.

  For the purpose of improving the operability when pushing the catheter from the outside of the body along the guide wire, efficiently transmitting the force applied to the catheter to the tip, and preventing the catheter from being kinked A core wire may be provided in the catheter. The core wire may be arranged in any part of the catheter, but has a rear end side opening of the guide wire lumen in the middle of the front end side shaft, and the rear end side of the front end side shaft is harder than the front end side of the front end side shaft and It is preferable that a core wire for adjusting the flexibility of the rear end side of the front end side shaft is arranged so as to be softer than the rear end side shaft, and the shape and dimensions of the core wire are the front end side shaft and the rear end side shaft. It can be determined in consideration of the size, material, purpose of use of the catheter, and the like. FIG. 6 shows an embodiment of the shape of the core wire, but the shape and dimensions of the core wire are not limited by this embodiment. In one embodiment shown in FIG. 6, it is preferable that the core wire intermediate portion having a tapered shape whose outer diameter decreases toward the front end is located inside the rear end side of the front end side shaft. In the case of a PTCA balloon catheter, the core wire tip has an outer diameter of 0.08 mm to 0.45 mm, a length of 20 mm to 250 mm, preferably an outer diameter of 0.10 mm to 0.40 mm, and a length of 30 mm to 200 mm. The core wire intermediate portion has a length of 10 mm to 120 mm, preferably 50 mm to 90 mm, and the outer diameter may be the same as the outer diameter of the core wire front end portion and the core wire rear end portion. The outer diameter of the core wire rear end may be the same as that of the core wire front end, and the length is 5 mm to 50 mm, preferably 10 mm to 30 mm.

  As long as the core wire is a metal, the material type is not particularly limited and can be determined in consideration of the dimensions and materials of the front and rear shafts, the purpose of use of the balloon catheter, etc. From the viewpoint of safety, stainless steel or nickel titanium alloy is preferable. In addition, a method for producing a taper-shaped portion such as a core wire middle portion or a core wire tip portion on the core wire is not particularly limited, and a known method such as centerless grinding is preferably used. .

When the catheter is a balloon catheter, there are dipping molding, blow molding, and the like as balloon manufacturing methods, and an appropriate method can be selected according to the intended use. In the case of a balloon catheter for dilatation treatment of the stenosis of the coronary artery of the heart, blow molding is preferable in order to obtain sufficient pressure strength. An example of a method for producing a balloon by blow molding is shown below. First, a tubular parison having an arbitrary size is formed by extrusion molding or the like. The tubular parison is placed in a mold having a mold that matches the balloon shape, and stretched in the axial direction and the radial direction by a biaxial stretching process, thereby forming a balloon having the same shape as the mold. In addition, a biaxial stretching process may be performed on a heating condition and may be performed in multiple times. Further, the axial stretching may be performed simultaneously with or before or after the radial stretching. Furthermore, an annealing process may be performed to stabilize the shape and dimensions of the balloon.
The balloon has joints on the straight pipe part and the front end side and the rear end side thereof, and has a tapered part between the straight pipe part and the joint part. The size of the balloon is determined by the intended use of the balloon catheter, but the outer diameter of the straight tube portion when expanded is 1.00 mm to 35.00 mm, preferably 1.25 mm to 30.00 mm. Is 5.00 mm to 80.00 mm, preferably 7.00 mm to 60.00 mm. In the case of a balloon catheter that expands and treats a stenosis of a coronary artery of the heart, the outer diameter of the straight tube portion when expanded is preferably 1.25 mm to 5.0 mm, and the length of the straight tube portion is 7 It is preferably 0.000 to 40.00 mm.

  The resin type of the tubular parison is not particularly limited, and for example, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane and polyurethane elastomer can be used, and two types of these resins can be used. A blend material obtained by mixing the above or a material having a multilayer structure in which two or more kinds are laminated may be used.

  As for the catheter processing method, a method such as fusion can be used in the case of a combination of materials that can be adhered and fused with an adhesive. Moreover, when using an adhesive agent, the composition and chemical structure of the adhesive agent and the curing type are not limited. That is, from the viewpoint of composition and chemical structure, adhesives such as urethane type, silicone type, epoxy type, and cyanoacrylate type are preferably used. From the viewpoint of curing type, two-component mixed type, UV curable type, water absorption Adhesives such as a curable type and a heat curable type are preferably used. When using an adhesive, it is preferable to use an adhesive having a hardness after curing such that the rigidity of the connection site does not change discontinuously before and after the connection site, such as the material, dimensions, rigidity, etc. of the connection site It is possible to select an adhesive in consideration of the above. In addition, the connecting part may be heat-treated in order to reduce the diameter of the connecting part. In the case of a poorly adhesive material such as polyolefin, the connecting part is plasma treated with oxygen gas or the like to improve the adhesiveness. It is also possible to bond them after making them.

  When connecting by fusion, a core material having an arbitrary size and shape may be inserted in order to secure a necessary lumen. In this case, considering the removal of the core material after finishing the processing, the outer surface of the core material is coated with a fluorine-based resin such as polytetrafluoroethylene, polyparaxylylene, polymonochloroparaxylylene, etc. It is preferable to make the material easy to remove. The dimensions, cross-sectional shape, and the like of the core material to be used do not limit the effects of the present invention, and can be determined in consideration of workability during processing, a required cross-sectional area of the lumen, and the like.

  As a material constituting the adapter member, resins such as polycarbonate, polyamide, polyurethane, polysulfone, polyarylate, styrene-butadiene copolymer, and polyolefin can be suitably used.

  An X-ray opaque marker may be provided in order to improve the visibility of a specific portion of the catheter during treatment using the catheter according to the present invention and to easily position the catheter. The radiopaque marker may be any material that has radiopacity, and any type of material such as metal or resin may be used. Further, the position, the number, and the like are not questioned and can be set according to the purpose of use of the catheter.

  Further, a hydrophilic coating can be applied to the outer surface of the catheter in order to facilitate insertion into a blood vessel or a guide catheter. That is, it is possible to apply a hydrophilic coating that exhibits lubricity when it comes into contact with blood on at least a part of the portion that comes into contact with blood, such as the front end side shaft and the rear end side shaft. However, the site where the hydrophilic coating is applied and the length of the coating can be determined according to the purpose of use of the catheter. The kind of hydrophilic coating does not limit the effect of the present invention, and hydrophilic polymers such as poly (2-hydroxyethyl methacrylate), polyacrylamide, and polyvinylpyrrolidone can be suitably used, and the coating method is not limited.

  When the catheter is a balloon catheter, depending on the intended use, a hydrophobic coating can be applied to the outer surface of the balloon so that the balloon does not slip when the balloon is expanded. The kind of the hydrophobic coating is not particularly limited, and a hydrophobic polymer such as silicone can be preferably used.

  Specific examples and comparative examples according to the present invention are described in detail below, but the present invention is not limited to the following examples.

  In addition, the pressability was evaluated in the example and the comparative example, and the sliding performance of the catheter and the guide wire, which is concerned about the narrowing of the clearance cross-sectional area of the guide wire to be used together with the inner shaft, was evaluated.

Example 1
A tube-shaped parison (inner diameter 0.40 mm, outer diameter 0.84 mm) was produced by extrusion molding using a polyamide elastomer (PEBAX7033SA01: manufactured by Arkema Corp.), and then biaxially stretched blow molding was performed using this parison. A balloon having an outer diameter of 3.0 mm and a straight tube length of 15 mm was produced.

  The inner shaft (inner diameter 0.30 mm, outer diameter 0.42 mm) is high-density polyethylene (HB530, Nippon Polychem Co., Ltd.), and the outer shaft (inner diameter 0.61 mm, outer diameter 0.71 mm) is polyamide elastomer (PEBAX7233SA01, manufactured by Arkema Co., Ltd.) ) Was used for extrusion molding. After joining the balloon and the outer tube by heat welding, the inner tube and the outer tube are arranged in a coaxial double tube, the balloon and the inner tube are joined by heat welding, and the outer tube and the inner tube are joined at 260 mm from the balloon tip. The cut one was used as a balloon shaft.

  Moreover, the core wire of the shape illustrated in FIG. 6 (core wire tip outer diameter: 0.12-0.35 mm, core wire tip length: 180 mm, core wire middle outer diameter: 0.35 mm, core wire middle length Length: 85 mm, core wire rear end outer diameter: 0.12-0.35 mm, core wire rear end length: 15 mm) was made of SUS304 stainless steel. SUS304 stainless steel core coated with polytetrafluoroethylene coating to secure inflation lumen is placed in the tip side shaft so that the portion of 100mm from the tip of the core wire is located at the rear end of the balloon shaft After that, another outer shaft is abutted against the rear end of the balloon shaft, and a polyamide elastomer tube (inner diameter: 1.00 mm, outer diameter: 1.10 mm) produced by extrusion molding is covered on the outer side. The other outer shaft was heat-welded to prepare the rear end side opening of the guide wire lumen as the front end side shaft.

  The rear end side shaft (inner diameter 0.45 mm, outer diameter 0.63 mm, length 1,100 mm) was made of SUS304 stainless steel. The front end side shaft and the rear end side shaft were bonded to each other with a two-component mixed urethane adhesive (UR0531, manufactured by HB Fuller) with a margin of 10 mm. A hub was formed by injection molding using polycarbonate (Makloron 2658, manufactured by Bayer), and bonded to the rear end of the rear shaft with a two-component mixed urethane adhesive (UR0531, manufactured by HB Fuller). . A balloon catheter was obtained by wrapping a balloon and sterilizing with ethylene oxide gas.

Since the guide wire used by the catheter was 0.010 inch (0.254 mm), the clearance cross-sectional area between the inner shaft and the guide wire was 0.08 mm ² .

(Comparative Example 1)
The inner shaft was 0.34 mm in inner diameter and 0.46 mm in outer diameter. Otherwise, a balloon catheter was produced in the same manner as in the example. Since the guide wire used by the catheter was 0.010 inches, the clearance cross-sectional area between the inner shaft and the guide wire was 0.14 mm ² .

(Comparative Example 2)
A balloon catheter was produced in the same manner as in the examples except that the inner shaft had an inner diameter of 0.43 mm and an outer diameter of 0.56 mm, and the outer shaft had an inner diameter of 0.74 mm and an outer diameter of 0.88 mm. Since the guide wire used by the catheter was 0.014 inch, the clearance cross-sectional area between the inner shaft and the guide wire was 0.18 mm ² .

(Comparative Example 3)
A balloon catheter was manufactured in the same manner as in Comparative Example 2 except that the inner shaft had an inner diameter of 0.41 mm and an outer diameter of 0.54 mm. Since the guide wire used by the catheter was 0.014 inch, the clearance cross-sectional area between the inner shaft and the guide wire was 0.13 mm ² .

(Pressability evaluation)
As shown in FIG. 9, an aortic arch model and a 6 French size guide catheter, and a guide wire having a guide wire diameter to be used in each catheter are passed through a water tank filled with physiological saline at 37 ° C. It passes through the bending plate and is set on the catheter together with the slide table. Attach a digital force gauge (FGC-0.5, Nidec Symposium) to the proximal part and the distal part of the catheter, and slide the catheter on the slide table (moving speed 10 mm / sec, moving distance: 10 mm). Measure the force applied to the hand and the tip of the catheter. The ratio of the force applied to the proximal portion of the catheter with respect to the force applied to the distal end portion of the catheter at that time was defined as a pressing property.

(Evaluation of guide wire slidability)
As shown in FIG. 10, an aortic arch model, a 6 French size guide catheter, and a guide wire with a guide wire diameter to be used in each catheter are set in a water tank filled with physiological saline at 37 ° C. The distal end of the catheter is placed in a bending plate, the guide wire is set on a slide table, and a digital force gauge (FGL-0.5, Nidec Symposium) is attached to the rear end of the guide wire. The force applied when the guide wire is slid back and forth 10 mm is measured, and the average value is used as a guide for guide wire sliding performance.

(Evaluation results)
In the evaluation of pressability, Example 1 was 50%, Comparative Example 1 was 34%, Comparative Example 2 was 32%, and Comparative Example 3 was 36%. % Was also improved.

  Further, in the sliding performance of the catheter and the guide wire, which is concerned about the narrowing of the clearance cross-sectional area of the guide wire that should be used together with the inner shaft, the evaluation is made in the example and the comparative example 2 (the clearance cross-sectional area is the largest). Went. As a result, the average sliding load was 11.8 gf in Example 1 and 13.9 gf in Comparative Example 2, and no deterioration in the guide wire sliding performance of the catheter in the Example was observed.

It is a schematic perspective view of an over-the-wire type (OTW type) among general balloon catheters. It is a schematic perspective view of a high-speed exchange type (RX type) among general balloon catheters. It is a partial schematic side view in which a guide wire lumen portion shows a longitudinal section of a coaxial structure in a general RX type balloon catheter. FIG. 4 is a cross-sectional view taken along the line A-A ′ of FIG. 3. It is a partial schematic side view which shows the longitudinal cross-section of a biaxial structure in the front end side shaft with a general RX type balloon catheter. It is A-A 'sectional drawing in FIG. It is the schematic perspective view which showed one Example of the core wire which concerns on this invention. It is a partial schematic sectional drawing which shows the clearance cross-sectional area of the guide wire which should be used together with the inner side shaft which concerns on this invention. It is a schematic diagram of the test which measures the pressability of the catheter concerning the present invention. It is a schematic diagram of the test which measures the guide wire sliding performance of the catheter which concerns on this invention.

Explanation of symbols

1 guide wire lumen 1A guide wire lumen distal side opening 1B guide wire lumen proximal side opening 2 second lumen (inflation lumen)
2A 2nd lumen (inflation lumen) opening 3 Hub 4 Strain relief 5 Balloon 5A Straight tube 5B Tip side taper part 5C Rear end side taper part 5D Tip side joint part 5E Rear end side joint part 6 Tip side shaft 6A Tip side Shaft front end side 6B Front end shaft rear end side 7 Rear end side shaft 8 Inner shaft 9 Outer shaft 10 X-ray opaque marker 11 Core wire 11A Core wire front end portion 11B Core wire intermediate portion 11C Core wire rear end portion 12 Dual lumen tube 13 Guide wire 14 Clearance cross section 15 Guide catheter 16 Bending plate 17 Digital force gauge 17A Catheter tip side digital force gauge 17B Catheter proximal side digital force gauge 18 Catheter 18A Cate Tel distal end 18B catheter proximal side 19 Y-type connector 20 water tank 21 the aortic arch model 22 slide table 23 guidewire

Claims (7)

A distal end side shaft composed of a resin tube, a rear end side shaft having higher rigidity than the distal end side shaft, a guide wire lumen capable of accommodating a guide wire therein and having a front end side opening and a rear end side opening The guide wire lumen extends in the distal direction of the catheter and forms the distal end opening at the most distal end of the catheter, and at the same time, the rear end opening in the middle of the distal shaft. A guide wire clearance cross-sectional area that is to be used together with the guide wire lumen is substantially the length direction of the guide wire lumen. A catheter characterized in that it is 0.04 to 0.12 mm ² throughout.   The catheter according to claim 1, wherein the guide wire to be used in combination has a nominal outer diameter of 0.010 inches.   The catheter according to claim 1, further comprising a core wire in the catheter.   The core wire is disposed in the catheter, and a rear end side (hereinafter referred to as a distal end side shaft rear end side) of the distal end side shaft of the guide wire lumen is referred to as the distal end side shaft. 4. The catheter according to claim 3, wherein the catheter is harder than a rear end side opening (hereinafter referred to as a front end side shaft front end side) of the guide wire lumen and softer than the rear end side shaft. .   The catheter according to claim 1, wherein the catheter is a balloon catheter.   An inner shaft forming a guide wire lumen and an outer shaft disposed so as to surround the inner shaft coaxially, and an inflation lumen is formed in an annular shape between the inner shaft and the outer shaft. The catheter according to claim 5.   The catheter according to claim 6, wherein a wall thickness of the inner shaft is 0.040 to 0.080 mm.

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