JP2008036391A - Balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a balloon catheter which does not cause positional shift of a balloon during expansion since the outer surface of the balloon has a high sliding friction factor, when the constriction part of lumen is expanded. <P>SOLUTION: The balloon catheter includes a shaft having at least one lumen penetrating in the longitudinal direction and a balloon placed at the shaft distal end part. The balloon has a braided layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a balloon catheter used for a treatment for expanding a stenosis occurring in a body cavity.

  In general, in order to treat a stenosis occurring in a body cavity such as a digestive tract such as an esophagus, a trachea, a bile duct, or a blood vessel, a balloon catheter is inserted into the body cavity to expand the stenosis. However, since the balloon material is often slippery, when the balloon is inflated at a high pressure to expand the stenosis, the balloon slips and deviates from the stenosis, that is, is displaced. There was something to do. In such a case, the balloon had to be deflated and re-expanded to the proper position, after which it was necessary to keep the balloon in an expanded state while taking care not to slip the balloon. For this reason, a series of operations takes time and effort, which hinders smooth treatment and increases the burden on the patient. In order to solve the problem, it is conceivable to reduce the expansion pressure of the balloon in order to prevent deviation from the stenosis of the balloon, but in that case, the stenosis cannot be sufficiently expanded, There is a possibility that the therapeutic effect of can not be expected.

  In Patent Document 1, an outer sleeve having a slit is placed on the balloon, and when the balloon is expanded, the slit is opened to make the balloon surface uneven, thereby improving the adhesion to the narrowed portion and preventing the slip. The balloon catheter which exhibits is disclosed. However, the balloon catheter described in Patent Document 1 does not always exhibit a sufficient anti-slip effect because the degree of opening of the slit changes depending on the expanded diameter of the balloon. Moreover, there is a possibility of tearing and breaking from the slit due to repeated expansion and contraction.

Patent Document 2 includes a balloon having an inner surface with a high coefficient of sliding friction and an outer surface with a low coefficient of sliding friction. When the balloon is contracted, the inner surface is covered with the outer surface, and when the balloon is expanded, the inner surface is exposed to the outside. A balloon catheter having improved adhesion to a stenosis is disclosed. However, since the balloon catheter described in Patent Document 2 has a portion with a high sliding friction coefficient and a portion with a low sliding friction coefficient, a sufficient anti-slip effect cannot be obtained depending on the contact surface with the narrowed portion, and the expanded balloon is inclined. There is a possibility.
JP 2005-278684 A Japanese Patent No. 036952424

  That is, an object of the present invention is to provide a balloon catheter that can reliably prevent displacement of the balloon when expanding a narrowed portion of a body cavity.

1. A balloon catheter comprising a shaft having at least one lumen penetrating in the lengthwise direction and a balloon disposed at the tip of the shaft, wherein the balloon has a braided layer on its outer surface. catheter.
2. 2. The balloon catheter according to 1 above, wherein the braided layer is made of an elastic fiber.
3. 3. The balloon catheter according to 2 above, wherein the surface of the braided layer is lubricated.
4). 4. The balloon catheter according to 1), 2) or 3) above, wherein the balloon catheter is used for a treatment for expanding a stenosis occurring in a body cavity.
5. 5. The balloon catheter according to 4 above, wherein the body cavity is an esophagus.

The balloon catheter of the present invention has a high sliding friction coefficient on the balloon surface, and the balloon is difficult to slide from the stenosis portion during expansion. Therefore, the therapeutic effect is high and the burden on the patient is minimized by smooth treatment.
Moreover, it maintains close contact with the surrounding tissue while maintaining a constant coefficient of sliding friction regardless of the expanded diameter of the balloon.
Further, a balloon catheter having an arbitrary sliding friction coefficient can be manufactured depending on the material, diameter, knitting method, or weaving method of the braided wire in the braided layer.
Furthermore, the braided layer expands only to the specified diameter, and in the unlikely event that the balloon ruptures due to overexpansion, the balloon will not burst into pieces or expand beyond a predetermined diameter. Therefore, the body cavity is not damaged and safety is high.

  The best mode of the balloon catheter according to the present invention will be described below.

  FIG. 1 is a side view showing a deflated balloon and its surroundings in a preferred embodiment of the balloon catheter of the present invention, and FIGS. 2 and 3 are side views showing the balloon and its surroundings in the balloon catheter shown in FIG. 1, respectively. It is a figure and a longitudinal cross-sectional view. FIG. 4 is a treatment method (procedures (1) to (4)) for a stenosis portion generated in a body cavity by the balloon catheter shown in FIG.

  The balloon catheter 1 shown in these drawings includes a long shaft 2 having at least one lumen penetrating in the length direction, an expandable / deflatable balloon 3 disposed at the distal end of the shaft, and a distal end of the balloon 3. It has the front-end | tip tip 8 arrange | positioned at the part.

  The shaft 2 has at least one lumen penetrating in the length direction. For this purpose, the shaft 2 preferably has a two-layer structure of an inner shaft 4 and an outer shaft 5, as shown in FIG. A plurality of inner shafts 4 may be provided, but a concentric two-layer structure of the inner shaft 4 and the outer shaft 5 is most preferable, and this embodiment will be described below as an example.

  The main lumen, that is, the lumen of the inner shaft 4 is used for insertion of a guide wire or injection of a drug solution such as a contrast medium. On the other hand, the secondary lumen, that is, the lumen other than the inner shaft 4 in the outer shaft 5, that is, the lumen between the inner shaft 4 and the outer shaft 5, is used for injecting an inflation fluid to be sent into the balloon. .

  The constituent material of the inner shaft 4 and the outer shaft 5 is, for example, a polyamide resin such as nylon 11 or nylon 12 or a polyamide elastomer, a polyolefin such as polypropylene or polyethylene, a polyester such as polyethylene terephthalate, a flexible material such as polyurethane or vinyl chloride. The high molecular material which has property is mentioned, Among these, it can use combining 1 type (s) or 2 or more types. Furthermore, for the purpose of providing the contrast of the shaft, for example, a contrast material such as barium sulfate or bismuth carbonate can be combined.

  Regarding the size of the inner shaft 4, the inner diameter should be 0.9 mm or more so that a generally used guide wire having an outer diameter of 0.035 inch or more can be inserted and a sufficient flow rate can be obtained even when a contrast medium is injected. Preferably, it is 1.0 mm or more. The outer diameter is preferably about 1.2 to 2.0 mm so as to have appropriate rigidity and flexibility.

  About the dimension of the outer shaft 5, an inner diameter is larger than the outer diameter of the inner shaft 4, and an outer diameter is about 3.0-4.5 mm so that it can have sufficient rigidity and a softness | flexibility.

  The length of the shaft 2 may be sufficient as long as necessary to place the balloon to the target site in the living body. However, if the length is longer than necessary, the operability is deteriorated. 1000 mm or more is more preferable, while 1500 mm or less is preferable and 1300 mm or less is more preferable.

  A hub (not shown) is installed at the base end of the shaft 2. The hub is formed with a port communicating with the main lumen and a port communicating with the sub-lumen. A balloon expansion device (not shown) such as a syringe can be connected to the port communicating with the secondary lumen.

  The balloon 3 is a flexible tubular membrane member, and in the case of the present invention, the balloon 3 is constituted by a resin layer 6 and a braided layer 7. The distal end portion 9 and the proximal end portion 10 of the balloon 3 are fixed in a liquid-tight manner over the entire circumference. The fixing method is not particularly limited, and examples thereof include adhesion using an adhesive and fusion using a laser.

  The constituent material of the resin layer 6 of the balloon 3 includes, for example, natural rubber / synthetic rubber, polyamide resin such as nylon 11 / nylon 12 or polyamide elastomer, polyolefin such as polypropylene / polyethylene, polyester such as polyethylene terephthalate, polyurethane, etc. Among the polymer materials, a polymer containing at least one kind can be mentioned, and natural rubber and synthetic rubber having high stretchability are particularly preferable.

A braided layer 7 is fixed outside the resin layer 6 of the balloon 3 so as to cover the balloon 3. The constituent material of the braided layer 7 may be woven fabric, knitted fabric or the like as long as it is relatively rich in stretchability. Preferred are elastic fibers such as polyester yarn, polyurethane yarn, nylon yarn and the like. The fineness of these single fibers is preferably 20 dtex (decitex) or more, more preferably 30 dtex or more, and preferably 100 dtex or less, more preferably 85 dtex or less. Further, the breaking elongation is preferably 10% or more, more preferably 15% or more. One or more of these can be knitted and used by any method. The knitting method of the braided layer 7 may be warp knitting or weft knitting as long as it is a method of knitting so as to have stretchability and pressure resistance. Preferably, weft knitting. More preferred is flat knitting.

  The braided layer 7 can be fixed to the balloon 3 by any method such as adhesion with an adhesive, fusion with a laser, or coating. Further, the braided layer 7 may be fixed not by the entire resin layer 6 but by a plurality of intermittent (interval) partial fixings. However, it is preferable that the braided layer is in close contact with the outer surface of the balloon, that is, if the braided layer is adhered or fused over the entire surface of the braided layer without any gap, it is difficult for the braided layer to come off the balloon in the body cavity.

  Such a braided layer 7 has elasticity enough to permit expansion of the balloon 3, and expands and contracts as the balloon 3 expands and contracts.

  The dimensions of the balloon 3 are not particularly limited. For example, when used for esophageal treatment, the balloon catheter at the time of dilation preferably has a maximum cross-sectional diameter of 10 to 30 mm in the direction perpendicular to the axial direction. More preferably, it is ˜30 mm. Further, the length in the axial direction is preferably 20 to 60 mm when expanded, and more preferably 30 to 50 mm.

  In the balloon catheter 1 of the present invention, since the braided layer 7 is provided on the balloon 3 in this manner, the friction between the narrowed portion of the living body and the surface of the balloon is increased, and an anti-slip effect is exhibited. Therefore, even when the balloon 3 is expanded at a high pressure, it is possible to reliably prevent the balloon 3 from slipping and being displaced from the narrowed portion.

  Further, when the braided layer 7 is fixed to the entire balloon 3, the maximum shape of the balloon 3 is defined, and even if the internal pressure of the balloon 3 is increased, the balloon 3 does not expand more than necessary. Even if 3 ruptures, it is safe to use because there is no risk of breaking into pieces or expanding beyond a predetermined diameter.

  Increasing the coefficient of sliding friction on the surface of the balloon 3 can prevent displacement when the balloon 3 is expanded, while reducing the operability when the catheter 1 is advanced inside the body cavity or positioned at the stenosis. There is sex. Therefore, when positioning the catheter 1 at the target treatment site, the guide wire should be operated in advance. Alternatively, a method of covering the balloon 3 with a sheath and removing the sheath before expansion can be employed. It is also possible to apply a lubricity treatment to the surface of the balloon 3 when deflated. Examples of the lubrication treatment include application of a lubricant such as silicone oil, olive oil, and glycerin, or coatings such as silicone, PTFE, maleic anhydride, polyvinyl pyrrolidone, and acrylamide. The material is not particularly limited as long as it is a material excellent in compatibility and improves the operability at the constriction. Silicone oil is preferred.

  Furthermore, it is preferable that a distal tip 8 for inserting the balloon 3 into the narrowed portion is provided on the distal end side of the balloon 3. The distal tip 8 has one main lumen penetrating in the length direction, and is used for insertion of a guide wire or injection of a drug solution such as a contrast medium. It must be inserted. The tip 8 can be fixed to the shaft by any method such as adhesion with an adhesive or fusion with a laser.

  The constituent material of the tip 8 is preferably an elastic material having appropriate flexibility and kink resistance, and examples thereof include polyamide elastomer and polyurethane.

  The shape of the tip 8 is preferably tapered in order to improve the insertion property to the narrowed portion or the closed portion, and the tip is preferably rounded to prevent perforation of the inner wall of the lumen.

  In general, the outer diameter of the distal tip 8 should be smaller than the outer diameter of the shaft, and the inner diameter should be such that a guide wire can be inserted and a contrast medium can be injected in the same manner as the inner diameter of the shaft. The length of the tip 8 is not particularly limited, but if it is too long, the kink resistance may be lowered, so that it is preferably 20 mm or less, and more preferably 10 to 15 mm.

  The balloon catheter of the present invention can be used for the treatment of expanding a stenosis occurring in a body cavity, for example, a stenosis occurring in a digestive tract such as an esophagus, a trachea, a bile duct or a blood vessel, taking advantage of the above-described features. is there. In particular, even in an esophagus that is covered with mucous membrane and has high slipperiness, it can be suitably used for dilatation treatment of a stenosis.

It is a side view which shows the balloon vicinity of the deflated state in suitable embodiment of the balloon catheter of this invention. It is a side view which shows the balloon vicinity in the balloon catheter shown in FIG. It is a longitudinal cross-sectional view which shows the balloon vicinity in the balloon catheter shown in FIG. Method for Treating Stenosis with Balloon Catheter Shown in FIG. 1 (Procedures (1) to (4))

Explanation of symbols

1: balloon catheter 2: shaft 3: balloon 4: inner shaft 5: outer shaft 6: resin layer 7: braided layer 8: distal tip 9: distal end 10 of balloon 3: proximal end 11 of balloon 3: lumen Constriction

Claims (5)

  A balloon catheter comprising a shaft having at least one lumen penetrating in the lengthwise direction and a balloon disposed at the tip of the shaft, wherein the balloon comprises a braided layer on the outer surface thereof. catheter.   The balloon catheter according to claim 1, wherein the braided layer is made of an elastic fiber.   The balloon catheter according to claim 2, wherein the surface of the braided layer is lubricated.   The balloon catheter according to claim 1, 2, or 3, wherein the balloon catheter is used for a treatment for expanding a stenosis portion generated in a body cavity.   The balloon catheter according to claim 4, wherein the body cavity is an esophagus.

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