JP2010035660A - Balloon catheter and stent delivery catheter for medical use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a balloon of a balloon catheter and a stent delivery catheter from forming the shape of a banana when it is expanded. <P>SOLUTION: An internal tube 2a, at least partially, is made of the same or a different material. The inner diameter and the outer diameter of the internal tube explains that a stretchable section having different inner and outer diameters expands as a balloon 1 expands and stretches. Consequently, the balloon catheter and the stent delivery catheter do not bend to make the shape of a banana, and their slidability is not affected as they do not firmly touch to a guidewire due to a radial contraction of the stretchable section. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a medical balloon catheter used for dilating a stenotic vascular vessel, inserted into a vascular vessel such as a blood vessel, esophagus, trachea, urethra, bile duct, etc. The present invention relates to a stent delivery catheter.

  Balloon catheters and stents are widely used to dilate a stenosis formed in a body vessel and secure a route. A stent is folded and placed in a catheter called a delivery catheter, inserted into the body, and expanded.

  Balloon catheters include a high-speed exchange type catheter that requires a guide wire lumen in a part of the entire shaft, and an over-the-wire type catheter in which a guide wire lumen exists in the entire shaft.

  There are two types of known delivery catheters. One is a balloon-expandable stent in which a balloon expanded by a pressure fluid using a conventional balloon catheter expands the stent by its expansion force. is there. The other is a self-expandable stent having an expandability formed by a shape memory alloy or the like.

  In the case of a balloon catheter or a balloon-expandable stent delivery catheter, the balloon may be expanded in a bent state like a banana. If the constricted vessel is expanded in such a curved state, the vessel is bent and expanded from the original position. This curvature causes the blood vessel to expand in a different shape than usual, which may cause vascular rupture and excessive expansion / contraction. On the other hand, in the case of a balloon expandable stent, the stent is also expanded along the expanded shape of the balloon. Therefore, when the balloon is bent in a banana shape, the stent is expanded as it is while being bent and is left in the same shape. As a result, the indwelled vessel is maintained in a curved shape, and may deviate from the conventional position and cause restenosis. Such balloon curvature may be caused by the shaft structure of the balloon catheter. When pressurized, the balloon is expanded in the axial direction and the radial direction, and the inner tube and the outer tube constituting the shaft do not follow the expansion of the balloon. Therefore, since the balloon cannot extend in the axial direction, the balloon is curved in the radial direction.

  The following prior art documents disclose a method that enables extension or movement of an inner tube or an outer tube.

  In Patent Document 1, the inner tube is configured to be nested, and each inner tube is nested so that the length of the inner tube can be expanded and contracted according to the expansion and contraction of the balloon to prevent the inner tube from being bent. Any expansion or contraction of the balloon caused by deflation can be accommodated. However, with this technique, it is difficult to produce a telescopic mechanism that can be telescopically stretched and maintain airtightness, and by placing such a structure in or near the balloon, the profile increases and the catheter outer diameter increases. Moreover, since the flexibility is deteriorated by this mechanism, there is a concern that the insertion into the body is deteriorated.

  Patent Document 2 discloses a technique in which an inner tube constituting a guide wire lumen can be extended as the balloon is extended. An extension portion is formed in a part of the inner tube, and when the extension portion extends, the inner diameter of the extension portion becomes smaller and the guide wire is reduced to the outer diameter. By this reduction, the inner diameter of the elongated portion is brought into close contact with the guide wire, so that no further fluid flows into the gap and acts as a valve. However, it is technically difficult to configure the extending portion, and the profile becomes large because a material for extending to the outside of the inner tube is joined. And since this expansion | extension part is arrange | positioned in a balloon, the profile of the folded balloon part becomes large, a softness | flexibility is also impaired and the permeability | transmittance to a body worsens. There is no description to prevent the expanded balloon from bending into a banana shape.

  Patent Document 3 discloses a technique in which an inner tube is inserted into an outer tube and can move to the distal end side of the inner tube as the balloon expands, and can move to the rear end side when the balloon is deflated. This technique prevents overstretching of the inner tube due to balloon expansion and prevents sagging of the inner tube when the balloon is deflated. However, since a mechanism for moving the inner pipe to the manifold portion is required, the production process is difficult and the number of steps is increased. Moreover, there is no description which prevents the expanded balloon from bending in a banana shape.

  In Patent Document 4, the inner diameter and the outer diameter of the inner tube and the outer tube are gradually reduced, and the shaft is configured in a nested manner. The shaft length can be changed by pulling out each tube from this nested state. However, there is no description for preventing the change in the length of the shaft accompanying the expansion of the balloon and the bending to the banana shape.

These prior arts require complicated mechanisms for nesting and moving or expanding / contracting the inner tube, and mechanisms for changing the length of the inner tube, making it difficult, time consuming and poorly productive. There is a problem. Further, by arranging these mechanisms in the balloon or the shaft, the profile becomes large, and the continuity of the rigidity of the shaft is deteriorated, leading to kinks. Furthermore, the insertion property of the catheter: trackability performance is also deteriorated.
Special table 2007-503963 Special table hei 7-50595 Noto 2518722 Special table 2001-519675

  The problem to be solved by the present invention is to provide a balloon catheter in which an expanded balloon is not bent into a banana shape, and a stent delivery catheter.

  In order to solve the above problems, the present invention has the following features.

  That is, the present invention is a medical balloon catheter having a balloon, an inner tube, and an outer tube, wherein the inner tube extends in the axial direction as the balloon expands, and further in the axial direction as the expanded balloon contracts. The present invention relates to a medical balloon catheter having at least one stretchable portion that contracts.

  The present invention also relates to a medical balloon catheter in which the expandable portion has a larger inner diameter than the inner tube.

  The present invention also relates to a medical balloon catheter in which the expandable portion has an inner diameter and an outer diameter larger than the inner tube.

  The present invention also relates to a medical balloon catheter in which the expandable portion is made of the same material as the inner tube.

  The present invention also relates to a medical balloon catheter in which the stretchable part is made of a material different from that of the inner tube.

  The present invention also relates to a medical balloon catheter in which a connecting portion between the inner tube and the expandable portion has no step and smoothly has a lumen.

  The present invention also relates to a medical balloon catheter in which a connecting portion between the inner tube and the extendable portion is tapered and a lumen is connected.

  The present invention also relates to a medical balloon catheter in which a connecting portion between the inner tube and the expandable portion has an arc shape and a lumen is connected. The present invention also relates to a medical balloon catheter having a balloon and an inner tube and an outer tube, wherein at least a part of the inner tube has a bellows shape.

  The present invention also relates to a stent delivery catheter in which a stent is reduced in diameter to the balloon of the medical balloon catheter.

  Other features of the present invention and their advantages will become apparent from the following embodiments and drawings.

  According to the present invention, a balloon catheter and a stent in which the inner tube expands and contracts following the expansion of the balloon, thereby suppressing the balloon from being bent into a banana shape and having no complicated mechanism in the vicinity of the balloon. A delivery catheter is provided. The contraction in the radial direction of the expansion / contraction part does not cause close contact with the guide wire, so that the slidability does not deteriorate.

  Embodiments of a balloon catheter and a stent delivery catheter according to the present invention will be described below with reference to the drawings. The catheter as an embodiment of the present invention is a known fast exchange type catheter as shown in FIG. 1 or an over-the-wire type catheter shown in FIG. The balloon-expandable stent delivery catheter is a known fast exchange catheter as shown in FIG. 3 or an over-the-wire catheter as shown in FIG. The catheter of the embodiment has a balloon on the distal end side of the catheter, includes a tube or lumen for flowing a pressure fluid through the balloon, and has any tube or lumen for passing a guide wire through at least a part of the shaft. The balloon catheter and the stent delivery catheter are not limited, and the inner tube expands and contracts following the expansion and contraction of the balloon.

  Hereinafter, the structure of the balloon catheter and the stent delivery catheter will be described in detail with reference to a coaxial type high-speed exchange type in which the outer tube and the inner tube are coaxial, and details of the embodiment of the present invention (such as a balloon provided in the catheter). Explained.

1. Overall Configuration of Balloon As shown in FIG. 1, the medical balloon 1 in the embodiment has a cylindrical straight tube portion and conical tapers at both ends thereof. As shown in FIG. 3 or 4, when the stent 6 is disposed by folding the balloon, the diameter is reduced on the straight pipe portion. Each of the straight pipe portion and each tapered portion has a cylindrical shape or a conical shape as an example, but the shape is not limited to such a shape and may be a shape well known to those skilled in the art.

2. Balloon Material If the material of the medical balloon 1 is a biaxially stretchable material, the effect of the present invention is not affected. Polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane Elastomers can be used, and polyesters, polyester elastomers, polyamides, and polyamide elastomers are preferable from the viewpoint of having a compressive strength that sufficiently expands the stent and realizing thinness and flexibility.

3. Balloon Manufacturing Method A balloon is produced by blow molding in which pressure is applied in a heated mold using a tube called a parison. The method for producing the balloon is not limited to this method, and may be a method for producing the balloon by dipping a resin outside the mold. As a method for producing a balloon, there are dipping molding, blow molding and the like, and it is possible to select a suitable method. However, blow molding is preferable in order to realize sufficient pressure resistance necessary for a balloon for stent expansion. . For example, first, a tubular parison having an arbitrary size is formed by extrusion molding or the like. A balloon having the same shape as the mold shape can be formed by disposing the tubular parison in a mold having a shape corresponding to the balloon shape and stretching it in the axial direction and the radial direction by a biaxial stretching process. . The axial stretching may be performed simultaneously with or before or after the radial stretching, and may be annealed to stabilize the shape and dimensions of the balloon.

4). Examples of materials for inner pipe, outer pipe, and hub In the case of a coaxial structure with a coaxial double pipe, the inner pipe 2 is polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, etc. Although it can be used, since the guide wire lumen is defined by the inner surface of the inner tube, in consideration of the slidability of the guide wire, polyethylene, particularly high-density polyethylene is preferable. In addition, the inner tube may have a multilayer structure, and the innermost layer may be made of high-density polyethylene and the outermost layer may be made of a material that can be bonded or fused to the balloon in order to ensure the slidability of the guide wire. Furthermore, in order to further improve the slidability of the guide wire, it is possible to apply a lubricious coating such as silicon or polytetrafluoroethylene on the inner surface of the inner tube. In addition, it is preferable to use a material that is more flexible than the inner tube 2 for the stretchable portion 9 that is disposed at least one in the inner tube 2.

  The material of the outer tube 3 is not particularly limited as in the case of the inner tube, and polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer and the like can be used. In addition, when the outer tube needs to have greater rigidity in order to improve operability, a metal tube may be connected to the proximal end side. The metal tube may be made of stainless steel or other metal, and may have an antithrombogenic coating on the outside thereof.

  As a material constituting the hub 5 or the manifold 6, polycarbonate, polyamide, polyurethane, polysulfone, polyarylate, styrene-butadiene copolymer, polyolefin, or the like can be preferably used.

5). Each joining method of a balloon, an outer tube, and an inner tube The joining method of a balloon, an outer tube, and an inner tube is not specifically limited, The adhesion | attachment by the well-known adhesive agent, the fusion | fusion by heat | fever, etc. can be used. Further, the composition and chemical structure of the adhesive used and the curing type are not limited. From the point of composition and chemical structure, adhesives such as urethane type, silicone type, epoxy type and cyanoacrylate type can be used. From the point of curing type, two-component mixed type, UV curable type, water absorption curable type Adhesives such as heat curing type and radiation curing type can be used. However, in the case of using an adhesive, after the curing, the rigidity of the joint does not change discontinuously before and after the joint at the joint between the rear end of the balloon and the outer tube and between the balloon tip and the inner tube. It is preferable to use an adhesive having a hardness of 5 mm, which can be selected in consideration of the rigidity of the balloon, outer tube, and inner tube.

6). Structure of Inner Tube As a structure of the inner tube, FIG. 5 (a) shows an inner tube 2a of a prior art catheter in which the inner tube is composed of a single material and size. As for the embodiment of the present invention, FIG. 5 (b) shows an embodiment in which a part of the inner tube has a stretchable portion 9a made of a different material with the same dimensions as the inner tube 2a. As another embodiment, in the embodiment shown in FIG. 6 (a), the inner tube 2b has the same material and the same outer diameter as the inner tube 2a, but has a stretchable portion 9 with a part of the inner diameter different from 2b. is doing. In the embodiment shown in FIG. 6 (b), an expansion / contraction portion 9b which is the same material as the inner tube 2a and differs only in inner diameter is connected to a part of the inner tube 2a. In the embodiment shown in FIG. 6 (c), a stretchable portion 9c having a different material and different inner diameter from the inner tube 2a is connected to a part of the inner tube 2a. In addition, you may have one or more of these expansion-contraction parts.

  In the embodiment shown in FIG. 7A, the inner tube 2c has the same material and the same dimensions as the inner tube 2a, but a part of the expansion / contraction part 9 has a different inner diameter and outer diameter. have. In the embodiment shown in FIG. 7 (b), a part of the inner tube is connected to an expansion / contraction portion 9d having the same material and different inner and outer diameters as the inner tube 2a. In the embodiment shown in FIG. 7 (c), a part of the inner tube is connected to a stretchable part 9e having a different material and inner diameter and outer diameter from the inner tube 2a.

  In addition, you may have one or more of these expansion-contraction parts.

  Moreover, as a structure of the inner tube in the present invention, a part of the inner tube 2 may have a bellows structure 11 as shown in FIG. The bellows structure 11 can be made of the same material as the inner tube 2 or a different material. One or more bellows structures may be provided.

  For the production of the inner tube having different inner diameters, in the case of the same material, it is possible to produce the bump tube by changing the inner diameter and the outer diameter during the tube extrusion process. When connecting tubes having different diameters, they can be connected by bonding with an adhesive or heat welding by hot melting. The method of producing a tube by dipping using core materials having different diameters is not particularly limited. When connecting tubes with different inner and outer diameters, the taper shape 11 shown in FIG. 9 (a) or the rounded shape shown in FIG. 9 (b) is used so that the guide wire passing through the lumen does not get caught in the joint of the tubes. It is preferable that the inner diameter is smoothly changed with a shape 12 (a rounded shape). To create a smooth lumen, the diameter is different, and the boundary is passed through the lumen of the inner tube using a taper or rounded core material. Perform welding. Alternatively, there is no particular limitation such as producing an inner tube by dipping using a core material in which the inner diameter changing portion is processed into a tapered shape or a round shape.

  Also in the conventional technology, when a flexible material is used for the inner tube, the inner tube can be extended with the expansion of the balloon. Shrink in the radial direction. However, when the guide wire is inserted into the inner tube lumen, the contraction in the radial direction is terminated when the inner tube comes into close contact with the surface of the guide wire. When the inner tube is in close contact with the surface of the guide wire, extension in the axial direction is also hindered, and the inner tube cannot be extended. Furthermore, when the inner tube contracts in the radial direction and comes into close contact with the guide wire, the slidability of the guide wire also deteriorates. Also, the larger the area that is in close contact with the guide wire, the greater the frictional resistance and the worse the slidability. On the other hand, in the present invention, since the inner tube is equipped with at least one expansion / contraction portion, when the inner tube expands with the expansion of the balloon, the inner diameter of the expansion / contraction portion is larger than the inner tube, so only the expansion / contraction portion Extends in the axial direction and contracts in the radial direction, and portions other than the stretchable part do not adhere to the guide wire. Therefore, even if the entire inner tube extends in the axial direction, the inner tube can be expanded straight without preventing the balloon from extending in the axial direction. More preferably, the length of the expansion / contraction part is shortened and arranged at several places, and the contact area is reduced when it is in close contact with the guide wire.

7). Example of material of hydrophilic coating A hydrophilic coating may be applied to the outer surface of the catheter in order to facilitate insertion into a blood vessel or a guide catheter. It is preferable to apply a hydrophilic coating that exhibits lubricity when in contact with blood on at least a portion of the shaft that contacts the blood of the catheter. The kind of hydrophilic coating does not limit the effect of the present invention, and hydrophilic polymers such as polyethylene glycol, polyacrylamide, and polyvinylpyrrolidone can be suitably used, and the coating method is not limited.

  In the delivery catheter, when a hydrophilic coating is present on the balloon surface, the stent is easily detached. Therefore, the hydrophilic coating is not applied to the balloon surface or is removed only on the balloon from above the hydrophilic coating. In order to increase the frictional resistance, a layer having a large coefficient of friction such as urethane or rubber can be provided.

8). Stent The stent according to the present invention (for example, a body cavity opening stent) may be a balloon expandable stent, and the material is not particularly limited, but stainless steel such as SUS316L, cobalt chromium alloy, or the like can be used. Further, the design of the stent is not limited at all.

9. Diameter reduction of a stent In order to reduce the diameter of a stent, the stent is placed on the balloon by folding it into several sheets and winding it around the inner tube around the catheter axial direction. It is possible to fold the balloon into two or more by techniques known to those skilled in the art. As for the method of winding, as long as there are two sheets, a method of winding a folded balloon in the same rotational direction (S wrap) and a method of winding each in the opposite direction (C wrap) can be used. If there are three or more sheets, a method of winding in the same direction is generally used.

  The position at which the stent is reduced in diameter after folding is preferably arranged on a straight tube when the balloon is folded into at least two sheets and wound around the catheter axial direction.

  In order to reduce the diameter of the stent to the delivery catheter, it is preferable that the entire circumference is uniformly reduced by applying a uniform force from the outside of the stent. If the crimping force is large, the stent is difficult to move, and the stent diameter after the diameter reduction is also small. More preferably, the diameter is reduced by a force of 50 N or more.

10. Stent Delivery Catheter FIG. 3 or 4 shows an example of a “stent delivery catheter” according to the present invention. This stent delivery catheter can be prepared by means well known to those skilled in the art.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples.

Example 1
A catheter was prepared according to the procedure described below. The overall structure of the catheter of Example 1 and the description of the structure are the same as the structure illustrated in the drawings and each structure described in the above embodiment.

  A tubular parison was produced by an extrusion method using a polyamide elastomer, and then a balloon was produced by a biaxial stretch blow molding method using this parison.

  The inner tube 2a (inner diameter 0.42mm, outer diameter 0.56mm) is polyethylene, and the expansion / contraction part 9a (inner diameter 0.42mm, outer diameter 0.56mm) consists of a three-layer tube. The outer layer is polyamide elastomer, the innermost layer is polyethylene, outer Tube 3 (inner diameter 0.76 mm, outer diameter 0.90 mm) is a polyamide elastomer, welding inner tube 14 (inner diameter 0.42 mm, outer diameter 0.56 mm) is a three-layer tube, the outer layer is a polyamide elastomer, and the innermost layer is polyethylene. Was produced by extrusion molding. As shown in FIG. 10, three expansion / contraction portions 9a cut to 20 mm were prepared and connected to the inner tube 2a at intervals of 60 mm so as not to be placed in the balloon. For the connection, a core material was inserted and the end of the expansion / contraction part 9a was expanded to overlap the end of the inner tube 2a, and a heat shrinkable tube was placed thereon to perform heat welding to connect the inner tubes. In order to weld each of the balloon 1 and the outer tube 3 to both ends of the connected inner tube, a welding inner tube 14 (the same tube as the inner tube 9 was connected as a welding white: 5 mm) was connected.

The rear end portion of the balloon and the front end portion of the outer tube were joined by heat welding, and the inner tube connected earlier was arranged in a coaxial double tube inside the outer tube, and the front end portion of the inner tube and the front end portion of the balloon were joined by heat welding. A transition portion was fabricated by heat welding the rear end portion of the outer tube and the rear end portion of the inner tube. In joining these, a core material of an arbitrary size coated with a highly lubricious material such as molded polytetrafluoroethylene was appropriately used to secure an inflation lumen or a guide wire lumen. A tube for inflation was extended from the transition part, and a hub was bonded to the rear end to produce a balloon catheter. The balloon catheter was provided with a hydrophilic coating.
While depressurizing the balloon catheter, the balloon was folded into a triset shape (a shape in which the balloon was folded into three blades).

(Example 2)
A catheter was prepared according to the procedure described below. The overall structure of the catheter of Example 1 and the description of the structure are the same as the structure illustrated in the drawings and the description of each structure described in the above embodiment.

  A tubular parison was produced by an extrusion method using a polyamide elastomer, and then a balloon was produced by a biaxial stretch blow molding method using this parison.

  The inner tube 2a (inner diameter 0.42mm, outer diameter 0.56mm) is polyethylene, and the stretchable part 9e (inner diameter 0.58mm, outer diameter 0.70mm) is a three-layer tube. The outer layer is polyamide elastomer, the innermost layer is polyethylene, outer The tube 3 (inner diameter 0.76 mm, outer diameter 0.90 mm) was produced by extrusion molding using a polyamide elastomer. As shown in FIG. 11, three inner tubes 14 cut to 20 mm were prepared and connected to the inner tube 2a at intervals of 60 mm so as not to be placed in the balloon. For the connection, a core material was inserted, the end of the expansion / contraction part 9e was overlaid on the end of the inner tube 2a, and a heat-shrinkable tube was placed thereon to perform heat welding to connect the inner tubes. By applying heat only to a part of the heat-shrinkable tube, heat shrinkage is insufficient in the other parts, so that the shrinkage is not completely performed, and the lumens of the joints of the tubes having different diameters are rounded and connected smoothly. In order to weld each of the balloon 1 and the outer tube 3 to both ends of the connected inner tube, a welding inner tube 14 (the same tube as the inner tube 9 was connected as a welding white: 5 mm) was connected.

The balloon rear end and the outer tube tip are joined by heat welding, the inner tube is arranged in a coaxial double tube in the outer tube, and the inner tube tip and balloon tip are joined in the shape shown in FIG. 12 by heat welding. . A transition portion was fabricated by heat welding the rear end portion of the outer tube and the rear end portion of the inner tube. In joining these, a core material of an arbitrary size coated with a highly lubricious material such as molded polytetrafluoroethylene was appropriately used to secure an inflation lumen or a guide wire lumen. A tube for inflation was extended from the transition part, and a hub was bonded to the rear end to create a balloon catheter. The balloon catheter was provided with a hydrophilic coating.
While depressurizing the balloon catheter, the balloon was folded into a triset shape (a shape in which the balloon was folded into three blades).

(Comparative Example 1)
A tubular parison was produced by an extrusion method using a polyamide elastomer, and then a balloon was produced by a biaxial stretch blow molding method using this parison.

  The inner tube 2a (inner diameter 0.42 mm, outer diameter 0.56 mm) was produced by extrusion molding using polyethylene, and the outer tube 3 (inner diameter 0.76 mm, outer diameter 0.90 mm) was produced by extrusion molding. As shown in FIG. 12, in order to weld each of the balloon 1 and the outer tube 3 to both ends of the inner tube 2, a welding inner tube 14 (the same tube as the inner tube 9 was connected as a welding sheath: 5 mm) was connected.

  The rear end of the balloon and the front end of the outer tube were joined by thermal welding, and the inner tube connected earlier was arranged in a coaxial double tube inside the outer tube, and the inner tube front end and the balloon front end were joined by thermal welding. A transition portion was fabricated by heat welding the rear end portion of the outer tube and the rear end portion of the inner tube. In joining these, a core material of an arbitrary size coated with a highly lubricious material such as molded polytetrafluoroethylene was appropriately used to secure an inflation lumen or a guide wire lumen. A tube for inflation was extended from the transition part, and a hub was bonded to the rear end to produce a balloon catheter. The balloon catheter was provided with a hydrophilic coating.

  While depressurizing the balloon catheter, the balloon was folded into a triset shape (a shape in which the balloon was folded into three blades).

(Evaluation of balloon expansion)
The balloon expansion performance of each of the produced samples (Examples 1 and 2 and Comparative Example 1) was evaluated. For the evaluation, pressurization was performed in 37 ° C. water using an indeflator, and the balloon expanded shape was evaluated with pressurization up to 20 atm.

(Evaluation results)
The balloon was expanded by pressurization, and in Examples 1 and 2, since the stretchable portion 9 was extended as shown in FIGS. 14 to 16, the balloon was expanded straight without bending into a banana shape. On the other hand, as shown in FIGS. 17 and 18 in Comparative Example 1, since the inner tube 2 cannot be extended without the expansion / contraction part, the balloon cannot be extended in the axial direction and is bent in the radial direction, showing a banana shape. . From these facts, it was confirmed that the inner tube can follow the expansion and contraction of the balloon by providing the stretchable part.

It is the schematic of a high-speed exchange type among common balloon catheters. It is the schematic of an over-the-wire type among general balloon catheters. It is the schematic of a rapid exchange type stent delivery catheter among general balloon catheters. It is the schematic of an over-the-wire type stent delivery catheter among general balloon catheters. It is an example of the inner tube | pipe structure which concerns on embodiment of this invention. It is an example of the inner tube | pipe structure which concerns on embodiment of this invention. It is an example of the inner tube | pipe structure which concerns on embodiment of this invention. It is an example of the inner tube | pipe structure which concerns on embodiment of this invention. It is an example of the inner tube | pipe structure which concerns on embodiment of this invention. It is an example of the balloon catheter which concerns on embodiment of this invention. It is an example of the inner tube | pipe structure which concerns on embodiment of this invention. It is an example of the balloon catheter which concerns on embodiment of this invention. It is an example of the general balloon catheter of this invention. It is an example of the expansion | extension of the inner tube | pipe which concerns on embodiment of this invention. It is an example of the expansion | extension of the inner tube | pipe which concerns on embodiment of this invention. It is an example of the balloon catheter which concerns on embodiment of this invention. It is an example of a general inner pipe. It is an example of the balloon catheter which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Balloon 2 Inner pipe | tube 2a Inner pipe | tube 2a without the change of the internal diameter of an inner diameter and an outer diameter 2b Inner pipe | tube with which the internal diameter of at least one part differs 2c Inner pipe | tube with a different internal diameter and outer diameter of at least one part 3 Outer pipe 4 Inflation tube 5 Hub 6 Manifold 7 guide wire entrance 8 stent 9 expansion / contraction part 9a expansion / contraction part with the same size and different material as the inner tube 2 9b expansion / contraction part with the same material and different inner diameter as the inner tube 2 9c expansion / contraction part with different material and different inner diameter from the inner tube 2 9d Stretchable part with the same material as the inner tube 2 but different inner diameter and outer diameter 9e Stretchable part with different material and the inner diameter and outer diameter different from the inner tube 2 Tube 15 Tensile force 16 Core material 17 Heat shrinkable tube

Claims (10)

  A medical balloon catheter having a balloon, an inner tube, and an outer tube, wherein the inner tube has an expandable portion that extends in the axial direction as the balloon expands and contracts in the axial direction as the expanded balloon contracts. A medical balloon catheter having at least one or more.   The medical balloon catheter according to claim 1, wherein the expandable portion has a larger inner diameter than the inner tube.   The medical balloon catheter according to claim 1, wherein the expandable portion has an inner diameter and an outer diameter larger than the inner tube.   The medical balloon catheter according to claim 1, wherein the stretchable part is made of the same material as the inner tube.   The medical balloon catheter according to claim 1, wherein the stretchable portion is made of a material different from that of the inner tube.   The medical balloon catheter according to any one of claims 1 to 5, wherein a connecting portion between the inner tube and the expandable portion has a step and has a smooth lumen.   The medical balloon catheter according to claim 6, wherein the connecting portion between the inner tube and the expansion / contraction portion is connected to a lumen in a tapered shape.   The medical balloon catheter according to claim 6, wherein a connecting portion between the inner tube and the expandable portion has an arc shape and a lumen is connected.   A medical balloon catheter having a balloon, an inner tube, and an outer tube, wherein at least a part of the inner tube has a bellows shape.   The stent delivery catheter which reduced the diameter of the stent to the balloon of the medical balloon catheter of Claims 1-9.

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