JP2008104660A - Medical balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical balloon catheter with high reachability to a lesion and high certainty of expansion treatment by generalizing the entire structure. <P>SOLUTION: The medical balloon catheter comprises a proximal end tube, an intermediate tube, a distal end tube, a guide wire passing tube and a balloon part. The guide wire passing tube exists from the inner side of the distal end tube to the inner side of the balloon part, a guide wire port which is the proximal end side opening of the guide wire passing tube exists at the proximal section of the distal end tube, a balloon is fixed to the distal end of the distal end tube and the distal end of the guide wire passing tube, and a distal end opening is provided on the distal end of the guide wire passing tube. The guide wire passing tube is an inner surface slidable polyimide tube. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a medical balloon catheter used for medical purposes, and more specifically, percutaneous angioplasty (PTA: Percutaneous Transluminal Angioplasty, PTCA: Percutaneous Transluminal Coronary Angioplasty, etc.).

  Conventionally, percutaneous angioplasty using a medical balloon catheter is widely used for the purpose of expanding or treating stenosis or occlusion in the lumen of the blood vessel and restoring or improving blood flow in coronary arteries and peripheral blood vessels. It has been. A typical medical balloon catheter is formed by joining a balloon that can be inflated and deflated by adjusting the internal pressure to the distal end portion of a catheter shaft. Inside the catheter shaft, a lumen through which a guide wire is inserted ( A guide wire lumen) and a lumen for supplying a pressure fluid for adjusting the internal pressure of the balloon (balloon expansion lumen) are provided along the longitudinal direction of the catheter shaft.

  A general operation example of PTCA using such a medical 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 is placed 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 medical balloon catheter is inserted along the guide wire to match the balloon with the stenosis. Next, a pressure fluid is supplied to the balloon via a balloon dilatation lumen using an indeflator or the like, and the balloon is inflated to dilate the stenosis. After dilatation treatment of the stenosis, PTCA is terminated by retracting the balloon under reduced pressure and removing it from the body. In this operation example, the use example of the medical balloon catheter by PTCA in the coronary artery stenosis is described. However, the medical balloon catheter is widely applied to the expansion treatment in other blood vessel lumens and body cavities such as the periphery. Yes.

  In such a medical balloon catheter, as shown in FIG. 1 or FIG. 2, the balloon 2 is joined to the tip of the catheter shaft 1, and the hub 3 for supplying pressure fluid for adjusting the internal pressure of the balloon is joined to the catheter shaft 1. It has a structure and is roughly classified into two according to the structure of the catheter shaft 1.

  One is that the guide wire lumen 4 is provided from the proximal end side to the distal end side of the medical balloon catheter, that is, over the entire length of the medical balloon catheter, and the guide wire port 5 is provided in the hub 3. It is an over-the-wire type (OTW type) (FIG. 1). The other is a high-speed exchange type (RX type) in which the guide wire lumen is provided only on the distal end side of the medical balloon catheter and the guide wire port 5 is provided in the middle of the catheter shaft 1 (FIG. 2). .

  The performance required for medical balloon catheters varies widely, but the main performance is the crossability of the stenosis site, the trackability to the bent blood vessel, and the force when inserting the medical balloon catheter into the blood vessel. There are three main categories of pushability. Moreover, kink-resistance is also mentioned as a performance related to pushability.

  Crossability improves by reducing the catheter shaft profile (thickness), but pushability and kink-resistance tend to decrease. In addition, increasing the rigidity of the catheter shaft improves pushability and kink-resistance, but tends to decrease trackability. That is, the above performances are closely related to each other, and it is not easy to improve all the performances. Accordingly, various techniques for improving crossability, pushability, and trackability and improving kink-resistance are disclosed.

  In Patent Document 1, there is provided a medical tube having a flexible inner layer, a reinforcing layer attached to the outside of the inner layer, and a flexible outer layer attached to the outside of the reinforcing layer, The reinforcing layer is a coil layer, at least part of which is composed of a first coil and a second coil that is provided substantially coaxially with the first coil and is wound in a direction opposite to the first coil. Each of the first coil and the second coil is wound in close winding with a gap width between pitches of 0.02 mm or less, and the coil layer extends from the distal end to the proximal end. Adhesive or resin is not bonded to the inner layer and the outer layer for a predetermined length toward the gap between the pitches on the base side of the coil layer in a portion extending from the base end of the medical tube to the predetermined length. Medical treatment characterized by inflow of materials A tube is presented. In addition, a vasodilator catheter using the medical tube is also presented.

  However, this configuration provides pushability and kink-resistance, but the first coil constituting the reinforcing layer and the first coil are provided substantially on the same axis and wound in the opposite direction to the first coil. Since the first coil and the second coil are overlapped with each other, the tube layer can be obtained with only a large thickness. You can't get something expensive. The guide wire passage tube of the vasodilator catheter is required to have a large inner diameter and a small outer diameter, that is, a thin tube. In addition, although an adhesive or a resin material is allowed to flow into the gap between the pitches on the proximal end side of the coil layer, this process is technically cumbersome and difficult. In addition, winding the coil around a tightly wound coil with a gap between the pitches of 0.02 mm or less gives sufficient flexibility to the tip as a vasodilator catheter even if the coil material is selected. That is, it is difficult to obtain trackability.

  Patent Document 2 discloses a balloon catheter assembly including an elongated tubular member having a balloon portion located on the distal side and a shaft portion located on the proximal side, and extends through the balloon portion and the shaft portion. A balloon catheter assembly is presented that includes a central lumen and an alternating braid member extending from the shaft portion distal to the balloon portion.

  Even in this configuration, pushability and kink-resistance can be obtained, but the reinforcing layer is composed of alternately braided members, that is, braided. In this case, since the strands constituting the reinforcing material overlap, the thickness of the tube is reduced. Only thick ones can be obtained. For this reason, a product with high crossability cannot be obtained.

Furthermore, in this document, a so-called OTW type vascular dilatation catheter is presented, but the gap in the braided tubular member functions as a fluid passage from between the inner lumen of the catheter to the balloon itself, or just distal to the balloon. It is complicated as an OTW type vasodilator catheter, such as inflating the balloon by injecting fluid after the part of the valve fits with the valve seat in the lumen and cooperates with the valve seat seen on the core wire or guide wire A core wire or a guide wire having a configuration and a unique valve seat is required, and there is a possibility that a sufficient vasodilator effect cannot be obtained in terms of the complexity of the procedure and the certainty.
Japanese Patent No. 3659664 Japanese Patent No. 3170210

  The main object of the present invention is to provide a medical balloon tube having, as main performances, good passability of a stenosis site, followability to a bent blood vessel, transferability of force when inserting a medical balloon catheter into the blood vessel, and kink resistance Is to provide. In particular, the object of the present invention is to improve the drawbacks of the prior art, such that the guide wire passes but the balloon body is difficult to pass by adding a device to the guide wire passing tube while maintaining their performance. An object of the present invention is to provide a medical balloon tube having improved lesion passage ability. In addition, the present invention provides reachability to the lesioned part and dilatation treatment by giving a stiffness to the distal part of the balloon catheter by combining the entire structure, such as using a core wire or a highly rigid guide wire passing tube. An object of the present invention is to provide a medical balloon tube with high reliability.

The present invention has one or more of the following features.
(1) One feature of the present invention is that the balloon portion is fixed to the proximal end tube (a), the intermediate tube (b), and the distal end constituting the lumen for balloon expansion from the proximal end side to the distal end side. And a guide wire passing tube having a tip opening at the tip, the balloon portion being fixed to the distal end, and covered with the tip tube (c) and the balloon portion. (D), wherein the intermediate tube (b) and the distal tube (c) have a balloon expansion lumen and a core wire inside the lumen; A guide wire port which is a proximal end side opening of the guide wire passing tube (d) is present at the proximal portion of the distal end tube (c), and the guide wire passing tube (d , It is a polyimide tube of the inner surface slidability is a medical balloon catheter, characterized in.
(2) In a preferred embodiment, the inner surface slidable polyimide tube has the following properties:
A nylon wire with an outer diameter of 0.4 mm is passed through the inner surface slidable polyimide tube with an inner diameter of 0.5 mm, wound around a cylindrical body with a diameter of 90 mm and fixed, and the nylon wire is 1 mm / min by a tensile tester. The sliding resistance load when pulled at a speed is 0.06 N or less,
It is.

  The above-described and other features of the present invention and their effects will be clarified by the following embodiments and drawings.

  ADVANTAGE OF THE INVENTION According to this invention, the medical balloon catheter which improved especially the narrow lesioned part permeability | transmittance is obtained by cooperation with the elasticity of a core wire using an inner surface slidable polyimide pipe | tube for a guide wire passage tube.

  Embodiments of a medical balloon catheter according to the present invention will be described below.

1. Overall Structure of Medical Balloon Catheter The medical balloon catheter as an embodiment is a high-speed exchange type (RX type) in which a guide wire passing tube 6 is disposed only at the distal end side of the medical balloon catheter as shown in FIG. It relates to a catheter. FIG. 3 shows the entire medical balloon catheter of the embodiment, but there are a hub 7, a strain relief 8, a proximal end tube 9, and a balloon 10.

  Further, FIG. 4 shows a detailed view from the distal portion of the medical balloon catheter, that is, from the balloon to a portion of the proximal tube. In the distal portion, there are a proximal end tube 9, an intermediate tube 11, a distal end tube 12, and a balloon 10 in order from the proximal portion. A guide wire passing tube 6 exists inside the distal end tube 12 and inside the balloon 10. These are bonded by thermal fusion or an adhesive.

  The proximal end tube 9 forms a balloon expansion lumen 18 as seen in the A-A ′ cross section (see FIG. 4A), and a position marker 13 may be provided.

  A core wire 14 is disposed in the intermediate tube 11 and the tip tube 12 for the purpose of increasing the rigidity of the distal side of the medical balloon catheter, and a position corresponding to a joint between the intermediate tube and the tip tube. The core wire fixing portion 15 is fixed by, for example, welding. B-B 'sectional view (refer to Drawing 4B) has balloon expansion lumen 18 by this core wire 14 and middle section tube 11. FIG.

  A guide wire passing tube 6 exists from the inside of the distal end tube 12 to the inside of the balloon 10. In the CC sectional view (see FIG. 4C), there is a balloon expansion lumen 18 formed by the guide wire passing tube 6, the core wire 14, and the distal end tube 12. A position marker 16 exists in the balloon 10. A proximal portion of the distal tube 12 has a guide wire port 17 which is a proximal end opening of the guide wire passage tube.

2. Balloon Balloon 10 is fixed to the distal end of tip tube 12 and the distal end of guide wire passing tube 6. A tip opening is provided at the tip of the guide wire passing tube 6.

  The balloon 10 can be inflated and deflated by adjusting the internal pressure. As a manufacturing method of the balloon 10, there are dipping molding, blow molding and the like, and an appropriate method can be selected according to the use application of the medical balloon catheter. In particular, in the case of a medical balloon catheter for the purpose of expanding and treating a stenosis of a blood vessel or a body cavity, blow molding is preferable in order to obtain sufficient pressure resistance. For example, a tubular parison having an arbitrary size is first 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, the said biaxial stretching process may be performed on heating conditions, and may be performed in multiple times. Further, the stretching in the axial direction may be performed simultaneously with or before or after the stretching in the radial direction. Furthermore, in order to stabilize the shape and dimensions of the balloon, the balloon may be annealed.

  As shown in FIG. 1 or FIG. 2, the balloon 10 has a straight pipe portion 2a and a joining portion 2b for liquid-tight joining to the distal end side and the proximal end side thereof, and is tapered between the straight pipe portion and the joining portion. It has a part 2c. The dimensions of the balloon 2 are determined by the intended use of the medical balloon catheter. The outer diameter of the straight tube portion 2a when expanded by adjusting the internal pressure is 1.50 to 35.00 mm, preferably 1.50. And the length of the straight pipe portion 2a is 10.00 to 80.00 mm, preferably 10.00 to 60.00 mm.

3. Material The resin material of the tubular parison is not particularly limited. For example, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane and polyurethane elastomer can be used. You may have the multilayer material by the blend material which mixed the seed | species or more, and the lamination | stacking of 2 or more types.

  The material of the base end tube 9, the intermediate tube 11, and the distal end tube 12 is not particularly limited. That is, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer and the like can be used.

  The material of the core wire 14 is stainless steel, C—Mn—Si—PS—Cr—Mo—Ni—Fe—X (X = Au, Os, Pd, Re, Ta, Ir, Ru) alloy, C—Mn. -Si-PS-Cr-Mo-Ni-X (X = Au, Os, Pd, Re, Ta, Ir, Ru) alloy, copper, nickel, titanium, piano wire, Co-Cr alloy, Ni-Ti Various alloys such as alloys, Ni—Ti—Co alloys, Ni—Al alloys, Cu—Zn alloys, Cu—Zn—X alloys (for example, X = Be, Si, Sn, Al, Ga), amorphous alloys, etc. Metal wires are used, and among these materials, stainless steel is preferable because it has an appropriate rigidity and is not workable, economical, or toxic. The core wire is preferably tapered so that it gradually becomes thinner in the intermediate tube region and has a constant diameter in the distal tube region.

  As the material of the position marker 16, it is preferable to use a metal having high radiopacity such as platinum or gold.

4). Physical Properties of Guide Wire Passing Tube 6 One of the characteristic configurations of the present invention is that the guide wire passing tube 6 is made of an inner surface slidable polyimide tube.

  As shown in FIG. 5, the “inner surface slidable polyimide tube” is a nylon body 20 having an outer diameter of 0.4 mm that is passed through an inner surface slidable polyimide tube 19 having an inner diameter of 0.5 mm. Polyimide having a sliding resistance load of 0.06 N or less observed when the nylon wire is pulled at a speed of 1 mm / min with a load cell 22 having a maximum measurement load of 1 N. It means a tube. In this sliding resistance load measurement, EZ-Tester made by Shimadzu Corporation was used.

  In this test method, as shown in FIG. 6, A is a value obtained by measuring the sliding resistance load of a polyimide tube having an inner diameter of 0.5 mm, which is normally available and does not involve any special consideration on the inner surface slidability. The sliding resistance load of the polytetrafluoroethylene tube having an inner diameter of 0.5 mm is expressed as B, and the sliding resistance load of the inner surface slidable polyimide tube is expressed as C. As can be seen from FIG. 6, the polyimide tubes that are usually available exceed the measurement limit of the load cell, and it can be seen that the inner sliding polyimide tube has a lower sliding resistance load than the polytetrafluoroethylene tube.

Such a polyimide tube with high inner surface slidability is obtained by converting a polyimide precursor into an imide, and has a water vapor transmission rate of 3 to 50 g / m ² · 24 h constituting the tube. .

As the polyimide precursor, for example, a precursor solution obtained by reacting a diamine or a derivative thereof with a tetracarboxylic dianhydride or a derivative thereof in a polar solvent, the paraphenylenediamine represented by the following chemical formula (A) And diaminodiphenylsulfone of the following chemical formula (B), 3,3 ′, 4,4-biphenyltetracarboxylic dianhydride of the following chemical formula (C), and pyromellitic dianhydride of the following chemical formula (D): A polyimide precursor solution having a main component can be used.

５．実施形態による効果
このようにして得られたガイドワイヤー通過用チューブは、これを用いて医療用バルーンカテーテルを構成した際、ガイドワイヤの通過性が良好で、コシがあり、折れにくい性質とコアワイヤの弾性等との協調によりその構造を総合して、狭小病変部への到達性、拡張治療の確実性が高い医療用バルーンカテーテルを得ることができる。

5. Advantages of the embodiment The guide wire passage tube thus obtained has a good guide wire passage property, a firmness, and is not easily broken when a medical balloon catheter is formed using the tube. A medical balloon catheter with high reachability to a narrow lesion and high reliability of dilatation treatment can be obtained by synthesizing its structure in cooperation with elasticity and the like.

6). Hydrophilic coating The outer surface of the medical balloon catheter can be provided with a hydrophilic coating in order to facilitate insertion into a blood vessel or a guide catheter. That is, it is preferable to apply a hydrophilic coating that exhibits lubricity when in contact with blood, such as a base end tube, an intermediate tube, a distal end tube, and an outer surface of a balloon, in contact with blood. The kind of hydrophilic coating is not particularly limited, and hydrophilic polymers such as poly (2-hydroxyethyl methacrylate), polyacrylamide, and polyvinylpyrrolidone can be suitably used, and the coating method is not limited.

FIG. 1 is a schematic perspective view of an over-the-wire type of a general PTCA balloon catheter. FIG. 2 is a schematic perspective view of a high-speed exchange type among general PTCA balloon catheters. FIG. 3 shows an overall configuration diagram of an embodiment of the present invention. FIG. 4 shows a distal portion of a medical balloon catheter as an embodiment of the present invention. FIG. 5 shows a method for measuring the inner surface slidability. FIG. 6 shows the sliding resistance load of each of a commonly available polyimide tube, polytetrafluoroethylene tube, and inner surface slidable polyimide tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Catheter shaft 2 Balloon 3 Hub 4 Guide wire lumen 5 Guide wire port 6 Guide wire passage tube 7 Hub 8 Strain relief 9 Base end tube 10 Balloon 11 Intermediate tube 12 End tube 13 Position marker 14 Core wire 15 Core wire Fixed portion 16 Position marker 17 Guide wire port 18 Balloon expansion lumen 19 Internal slidable polyimide tube 20 Nylon wire 21 Cylindrical body 22 with a diameter of 90 mm 22 Load cell

Claims (2)

From the base side to the tip side,
A proximal tube (a) constituting a lumen for balloon expansion,
Middle tube (b),
A tip tube (c) having a balloon portion fixed to the distal end; and
A medical balloon catheter having a tip opening at the tip, the balloon portion fixed at the distal end, and a guide wire passage tube (d) covered with the tip tube (c) and the balloon portion. Because
The intermediate tube (b) and the tip tube (c) have a balloon expansion lumen and a core wire inside the lumen,
In the proximal portion of the distal end tube (c), there is a guide wire port that is a proximal end side opening of the guide wire passing tube (d),
The guide wire passage tube (d) is an internally slidable polyimide tube,
A medical balloon catheter. The inner surface slidable polyimide tube has the following properties:
A nylon wire with an outer diameter of 0.4 mm is passed through the inner surface slidable polyimide tube with an inner diameter of 0.5 mm, wound around a cylindrical body with a diameter of 90 mm and fixed, and the nylon wire is 1 mm / min by a tensile tester. The sliding resistance load when pulled at a speed is 0.06 N or less,
The medical balloon catheter according to claim 1.

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