Patent Description:
<CIT> relates to a catheter having an outer tube assembly with an exterior covering, an interior covering and a braid and an inner tube assembly with an outer tube covering, an inner tubing and a braid.

<CIT> relates to a catheter having a first reinforcing material layer, a first resin outer layer and a hub as well as a second reinforcing material layer and a second resin outer layer. A balloon catheter as a medical device that widens a stenosed site formed in a living body has been known (see PTL <NUM>).

It is desirable that a medical instrument having a relatively elongated shape like a balloon catheter has a desired physical property such that a kink, breaking, or the like does not occur when the device is used in a living body. For example, with a guiding catheter, a microcatheter, or the like, an attempt to improve kink resistance (prevention of occurrence of folding during bending) or a tensile strength by embedding a metal reinforcing member such as a coil in a resin tube has been made. Similarly, with the balloon catheter, it is considered that it is possible to improve the kink resistance or the tensile strength by adding a metal reinforcing member to a shaft.

However, in a case of using a metal reinforcing member, compatibility between the reinforcing member and the shaft of the balloon catheter configured of a resin material is low, and thus it is difficult to achieve a sufficient bonding force therebetween. In addition, when a distal tip is attached to impart flexibility to a distal portion of the shaft, it is necessary to perform an end-portion treatment such that the metal reinforcing member is not dispersed on an end portion of the shaft.

On the other hand, regarding the shaft of the balloon catheter, there is a problem in terms of operability of a guide wire such as a decrease in sliding resistance of the guide wire inserted into a guide wire lumen or the improvement in insertability of the guide wire through the guide wire lumen.

An object of the present invention is to provide a balloon catheter by which it is possible to improve operability of a guide wire and it is possible to prevent various problems which can arise in a case of using a metal reinforcing member from arising.

According to the present invention, there is provided a balloon catheter according to claims <NUM> and <NUM>.

The balloon catheter configured as described above has the kink resistance or tensile strength improved by the reinforcing member provided on the inner side of the tubular body provided in the inner tube. In addition, in the inner tube of the balloon catheter, the first resin and the second resin are melt-solidified in the first region in vicinity of the distal opening portion. Therefore, the inner circumferential surface of the inner tube has small unevenness by the reinforcing member, and thus it is possible to prevent the guide wire from being caught on the reinforcing member in the vicinity of the distal opening portion. On the other hand, the sliding resistance of the guide wire due to the unevenness by the reinforcing member is decreased in the second region on the proximal side more than in the vicinity of the distal opening portion.

Since the tubular body and the reinforcing member of the balloon catheter both include the resin, the tubular body and the reinforcing member are easily fused together, compared to a case where the reinforcing member is formed of metal. Therefore, when an end portion of the inner tube is cut and the distal tip is attached, there is no need to perform an end-portion treatment for preventing dispersion of an end portion of the reinforcing member, and thus it is easy to perform a manufacturing operation.

Hereinafter, embodiments of the present invention will be described with reference to the figures. Note that a dimension ratio in the figures is enlarged depending on the description and the ratio is different from an actual ratio in some cases.

With reference to <FIG>, a balloon catheter <NUM> according to the embodiment is a medical device that performs a medical treatment by inserting an elongated shaft <NUM> through a biological organ and dilating a balloon <NUM> disposed on a distal side of the shaft <NUM> in a stenosed site (lesion area) to widen the stenosed site.

In the embodiment, the balloon catheter <NUM> is configured as a PTCA widening balloon catheter that is used to widen a stenosed site of a coronary artery; however, the balloon catheter <NUM> can be configured to be used for a purpose of performing a medical treatment and a remedy for a biological organ such as a stenosed site formed in another blood vessel, a bile duct, a trachea, an esophagus, another gastrointestinal tract, a urethra, an aurinasal lumen, or another internal organ, or the balloon catheter <NUM> can be configured as a balloon catheter for delivery which is used for a purpose of conveying a medical instrument such as a stent into a living body.

As shown in <FIG>, the balloon catheter <NUM> includes a shaft <NUM>, a balloon <NUM> that is disposed on a distal portion side of the shaft <NUM> and is capable of undergoing dilation deformation and deflation deformation depending on inflow and discharge of a pressurizing medium, and a hub <NUM> disposed on a proximal portion side of the shaft <NUM>.

In the present specification, a side on which a distal tip <NUM> is disposed in the balloon catheter <NUM> is referred to as a distal side, a side on which a hub <NUM> is disposed in the balloon catheter <NUM> is referred to as a proximal side, and a direction in which the shaft <NUM> stretches is referred to as an axial direction.

<FIG> is an enlarged cross-sectional view showing a part of a dashed line portion 2A shown in <FIG>, and <FIG> is an enlarged cross-sectional view of a part of a dashed line portion 2B shown in <FIG>.

The balloon catheter <NUM> is a so-called rapid exchange type provided with a proximal opening portion 104a through which a guide wire W is guided out to be closer to the distal portion side of the shaft <NUM>.

As shown in <FIG>, the shaft <NUM> is configured to have an inner tube <NUM> provided with a guide wire lumen <NUM> through which a guide wire W is inserted and an outer tube <NUM> that forms a pressurizing medium lumen <NUM> through which the pressurizing medium can circulate between the inner tube <NUM> and the outer tube <NUM>.

The shaft <NUM> has a double tube structure in which the inner tube <NUM> is interpolated into the outer tube <NUM>, and the inner tube <NUM> and the outer tube <NUM> are disposed to be concentrically arranged.

As shown in <FIG>, the inner tube <NUM> is provided with two opening portions of a distal opening portion 103a formed at the distal end and a proximal opening portion 104a formed at the proximal end. Inside the inner tube <NUM>, the guide wire lumen <NUM> that communicates with the opening portions 103a and 104a is extended.

The inner tube <NUM> is configured of a hollow tubular material, and the proximal side of the inner tube is curved outward in a radial direction.

A distal portion of the balloon <NUM> is bonded in vicinity of a distal end of the inner tube <NUM> in a liquid-tight and airtight manner by a known method of adhesion or the like. In addition, a portion in the vicinity of a proximal end of the inner tube <NUM> is bonded with a connecting opening portion <NUM> formed at a predetermined position of the outer tube <NUM> in a liquid tight and airtight manner. The guide wire W is inserted through the guide wire lumen <NUM> with the distal opening portion 103a provided at the distal end of the inner tube <NUM>, as an entrance, and with the proximal opening portion 104a provided at the proximal end of the inner tube <NUM>, as an exit.

The inner tube <NUM> is provided with a radiopaque contrast mark <NUM> representing a center position of the balloon <NUM> in the axial direction. For example, the radiopaque contrast mark <NUM> is formed by using a fine metal line having a small diameter which is made of a radiopaque material such as metal such as platinum, gold, silver, titanium, or tungsten or an alloy thereof. Note that the radiopaque contrast mark <NUM> may be formed by using a resin material including powder of the radiopaque material.

The distal tip <NUM> is attached to the distal end of the inner tube <NUM>. The distal tip <NUM> has a tapered shape having an outer diameter decreasing toward the distal side. The distal tip <NUM> has a through-hole <NUM> penetrating the distal tip <NUM> in an axial direction thereof inside. The through-hole <NUM> enables the guide wire W inserted through the guide wire lumen <NUM> of the inner tube <NUM> to be pulled outside the inner tube <NUM>.

For example, the distal tip <NUM> can be configured of a flexible resin member having a heat-shrinkable property. However, the material of the distal tip <NUM> is not particularly limited as long as the distal tip can be fixed to the inner tube <NUM>. Note that, in a case where the distal tip <NUM> is configured of a resin member, the distal tip <NUM> can be fixed to the inner tube <NUM> by fusion. As shown in <FIG>, the distal tip <NUM> is fixed in a state in which a proximal surface thereof is in a direct contact with the distal surface of the inner tube <NUM> and in a state in which an outer circumference of the proximal end of the distal tip <NUM> is covered with a distal end of the balloon <NUM>. However, the fixation of the distal tip <NUM> is not limited thereto. For example, the distal tip <NUM> may be fixed in a state of covering an outer circumference of the distal end of the inner tube <NUM> or may be fixed in a state of being inserted into the distal end of the inner tube <NUM>.

The outer tube <NUM> is configured to have a tubular member including a lumen extending from the vicinity of the proximal portion of the balloon <NUM> to the hub <NUM>. A proximal portion of the balloon <NUM> is bonded in the vicinity of a distal end of the outer tube <NUM> in a liquid-tight and airtight manner by a known method of adhesion or the like.

Examples of constituent materials of the outer tube <NUM> include polyolefin such as polyethylene, polypropylene, an ethylene-propylene copolymer, or an ethylene-vinyl acetate copolymer, a thermoplastic resin such as soft polyvinyl chloride, various types of rubber such as silicone rubber or latex rubber, various types of elastomers such as a polyurethane elastomer, a polyamide elastomer, or a polyester elastomer, and crystalline plastics such as a polyamide, crystalline polyethylene, or crystalline polypropylene. For example, it is possible to compound an antithrombotic substance such as heparin, prostaglandin, urokinase, or an arginine derivative with such substances described above and to obtain a material having antithromboticity.

As shown in <FIG>, the hub <NUM> is provided with a port <NUM> that is connectable to a supply device (not shown) such as an in/deflator for supplying a pressurizing medium in a liquid-tight and airtight manner. For example, the port <NUM> of the hub <NUM> can be configured of a known luer taper or the like which is configured such that a fluid tube or the like is connectable or separable.

The pressurizing medium (for example, a physiological salt solution or a contrast agent) that is used for dilating the balloon <NUM> can flow into the shaft <NUM> via the port <NUM> of the hub <NUM>. The pressurizing medium is supplied to the balloon <NUM> through the pressurizing medium lumen <NUM>.

As shown in <FIG>, the balloon <NUM> includes a straight dilation effecting portion (pressurizing portion), which widens along with dilation deformation, a stenosed site formed in a body lumen, and tapered portions provided at both of the distal side and the proximal side of the dilation effecting portion. The distal portion of the balloon <NUM> is fixed to an outer surface of the inner tube <NUM> on the distal side. The proximal portion of the balloon <NUM> is fixed to an outer surface of the outer tube <NUM> on the proximal side.

Constituent materials of the balloon <NUM> are not particularly limited, and examples thereof include polyolefin such as polyethylene, polypropylene, or an ethylene-propylene copolymer, polyester such as polyethylene terephthalate, a thermoplastic resin such as polyvinyl chloride, an ethylene-vinyl acetate copolymer, a crosslinked ethylene-vinyl acetate copolymer, or polyurethane, polyamide, a polyamide elastomer, a polystyrene elastomer, silicone rubber, latex rubber, and the like.

Next, a structure of the inner tube <NUM> will be described in detail.

As shown in <FIG>, the inner tube <NUM> includes a predetermined tubular body <NUM>, a reinforcing member <NUM> disposed on an inner side of the tubular body <NUM>, and an outer layer <NUM> disposed on an outer surface of the tubular body <NUM>.

As shown in <FIG>, the inner tube <NUM> has a first region <NUM> including the distal portion provided with the distal opening portion 103a and a second region <NUM> that is disposed to be closer to the proximal side than the first region <NUM>. In addition, as shown in <FIG>, the inner tube <NUM> has a third region <NUM> that is disposed to be closer to the proximal side than the second region <NUM>.

The distal tip <NUM> is disposed in the first region <NUM>. The proximal opening portion 104a of the inner tube <NUM> is disposed in the third region <NUM>.

The tubular body <NUM> has a hollow tubular shape extending in the axial direction of the inner tube <NUM>. Similar to the tubular body <NUM>, the outer layer <NUM> has a hollow tubular shape extending in the axial direction of the inner tube <NUM>.

The tubular body <NUM> is made of a predetermined first resin. In addition, linear bodies <NUM> constituting the reinforcing member <NUM> are made of a predetermined second resin having a melting point higher than that of the first resin.

As shown in <FIG>, the tubular body <NUM> is provided with a convex portion <NUM> on an inner surface <NUM> of the tubular body <NUM>. The convex portion <NUM> projects from the inner surface <NUM> toward an inner side in a radial direction (an inner side in a radiation direction) so as to penetrate a gap portion <NUM> formed in the reinforcing member <NUM>. Note that, in an example in the figures, axially orthogonal sections of the tubular body <NUM>, the reinforcing member <NUM>, and the outer layer <NUM> have a circular shape; however, the shape is not limited to the circular shape. For example, the cross section may have an elliptical shape, a rectangular shape, or the like.

The convex portion <NUM> is formed when a part of the first resin of the tubular body <NUM> is melted and flows into the gap portion <NUM>. A cross-sectional shape of the convex portion <NUM> shown in the figures is exemplified, and the shape of the convex portion <NUM> can be appropriately modified.

As shown in <FIG>, the reinforcing member <NUM> is formed of a plurality of linear bodies <NUM> which are braided. The reinforcing member <NUM> is provided with the gap portion <NUM> formed between the plurality of linear bodies <NUM>. In addition, the reinforcing member <NUM> has a tubular shape extending in the axial direction of the inner tube <NUM>.

The reinforcing member <NUM> has a function of increasing the kink resistance or the tensile strength of the inner tube <NUM> and a function of decreasing the sliding resistance of the guide wire W that is inserted through the guide wire lumen <NUM> of the inner tube <NUM>. A contact area between the inner surface <NUM> of the tubular body <NUM> and the guide wire W is decreased in a site in which the linear bodies <NUM> constituting the reinforcing member <NUM> project from the inner surface <NUM> of the tubular body <NUM>, and thus the sliding resistance is decreased.

For example, a one-over one-under structure in which the linear bodies <NUM> intersect each other can be employed as a braid structure of the reinforcing member <NUM>. However, the structure is not limited to such a structure.

For example, the linear body <NUM> can be formed of a wire having a circular cross-sectional shape. It is possible to decrease a contact area between the reinforcing member <NUM> and the guide wire W that is inserted through the guide wire lumen <NUM> of the inner tube <NUM> by using a circular wire, and thus it is possible to more suitably decrease the sliding resistance. In addition, the linear body <NUM> can be formed of a wire having an elliptical cross-sectional shape, for example. When the elliptical wires are used, an area of a site in which the wires overlap each other is increased. Therefore, it is possible to increase rigidity of the reinforcing member <NUM>. Note that the reinforcing member <NUM> can also be formed of wires having a rectangular cross-sectional shape, may be formed by combining the circular, elliptical, and rectangular wires, or can be configured of wires having a shape other than the exemplified cross-sectional shapes. An outer diameter or the like of the used wire is not particularly limited.

The reinforcing member <NUM> is made of the second resin having the melting point higher than that of the first resin of the tubular body <NUM>. When the reinforcing member <NUM> and the tubular body <NUM> are fused together, a part of the tubular body <NUM> is melted, whereas melting of the reinforcing member <NUM> is suppressed. Therefore, the shape of the linear body <NUM> of the reinforcing member <NUM> is maintained. For example, similar to the second region <NUM>, the contact area between the guide wire W and the inner surface <NUM> of the tubular body <NUM> is decreased in a region in which the shape of the linear bodies <NUM> is maintained, and thus the sliding resistance is significantly decreased. Note that, in the second region <NUM>, when the reinforcing member <NUM> and the tubular body <NUM> are fused together due to heating from the outer circumference of the tubular body <NUM>, a part of the reinforcing member <NUM> on the side of the tubular body <NUM> may also be melted.

For example, it is possible to use modified polyethylene (melting point: about <NUM>) as the first resin of the tubular body <NUM>.

It is possible to use, as examples of the second resin of the linear body <NUM>, polypropylene (melting point: about <NUM>), nylon <NUM> (melting point: about <NUM>), nylon <NUM> (melting point: about <NUM>), or nylon <NUM> (melting point: about <NUM>). However, the second resin may be a resin having a melting point higher than that of the first resin of the tubular body <NUM>, and it is possible to select any resin depending on a relationship with a material of the tubular body <NUM>.

In the embodiment, the linear bodies <NUM> constituting the reinforcing member <NUM> are formed of only the second resin. Therefore, it is possible to prevent the reinforcing member <NUM> and the guide wire W from being scratched against each other when the guide wire W is inserted through the guide wire lumen <NUM>, and it is possible to suitably prevent the guide wire W from being damaged or broken. In addition, regarding the inner tube <NUM>, since the tubular body <NUM> and the linear bodies <NUM> are formed of only the resin when a molding process is performed by using a mold or the like, it is possible to adjust an outer diameter, thickness, hardness, or the like by using fluidity of the resin. Therefore, the inner tube <NUM> is also excellent in processability.

Similar to the linear bodies <NUM>, the outer layer <NUM> is made of a resin having the melting point higher than that of the first resin of the tubular body <NUM>. For example, the resins exemplified as the resins of the linear bodies <NUM> can be used as the resin of the outer layer <NUM>. However, so long as the resin is a resin having a melting point higher than that of the first resin of the tubular body <NUM>, it is not limited. Similar to the second resin of the linear body <NUM>, it is possible to select any resin depending on a relationship with a material of the tubular body <NUM>.

In the second region <NUM> of the inner tube <NUM>, the contact area between the inner surface <NUM> of the tubular body <NUM> and the guide wire W is decreased, it is preferable that the shape of the convex portion <NUM> or the like is adjusted depending on the thickness of the linear bodies <NUM>. For example, a length d3 (refer to <FIG>) of the convex portion <NUM> of a site penetrating the gap portion <NUM> can be less than twice the thickness of the linear body <NUM> on a cross-section perpendicular to the axial direction of the inner tube <NUM>. This is because of the following reasons.

As shown in <FIG>, in a portion in which two linear bodies 121a and 121b overlap each other, the thickness of the reinforcing member <NUM> is the sum of dimensions of a thickness (outer diameter) d1 of the linear body 121a and a thickness (outer diameter) d2 of the linear body 121a. Hence, when the length d3 of the convex portion <NUM> of the site penetrating the gap portion <NUM> is less than the sum of the dimensions of both of the linear bodies 121a and 121b (less than twice the thickness of the linear body <NUM>), it is possible to prevent the convex portion <NUM> from projecting to the inner side in the radial direction more than the gap portion <NUM>, and it is possible to suitably decrease the sliding resistance of the guide wire W. Note that, similarly, even when the linear bodies <NUM> have a cross-sectional shape other than the circular cross-sectional shape, the length d3 of the convex portion <NUM> of the site penetrating the gap portion <NUM> is shorter than the total of the thickness dimensions of the braided sites, and thereby it is possible to suitably decrease the sliding resistance.

<FIG> is a view showing a cross-section of a site in which adjacent linear bodies 121a and 121b intersect each other (a cross-sectional view taken along line 6B-6B shown in <FIG>). In the site in which the plurality of linear bodies 121a and 121b intersect each other, at least one linear body 121b has a recessed shape. When heat is applied in order to fuse the tubular body <NUM> and the reinforcing member <NUM> in a state in which the linear bodies 121a and 121b are braided with each other, stress is concentrated on a contact site, and a concave portion <NUM> is formed by receiving an influence of the heat. When the concave portion <NUM> is formed, the linear bodies 121a and 121b are strongly caught on each other. Therefore, it is possible to still better maintain the tubular shape of the reinforcing member <NUM>, and thus it is possible to enhance a reinforcing function. Note that <FIG> shows an example in which the concave portion <NUM> is formed only on the one adjacent linear body 121b; however, the concave portion <NUM> may be formed on both of the linear bodies 121a and 121b depending on an applying state of the heat or an applying state of stress or may be formed only on the linear body 121a disposed on the side of the outer surface of the inner tube <NUM>. In addition, since it is possible to appropriately change a depth, a shape, or the like of the concave portion <NUM> depending on a condition or the like during the fusion, the shape thereof is not limited to the shape shown in the figure. In addition, the linear bodies 121a and 121b are disposed to be orthogonal to each other; however, the disposition is not limited to such disposition, and it is possible to appropriately change an angle of the site (intersecting site) in which the linear bodies <NUM> overlap each other.

Next, a state of the linear bodies <NUM> in every portion of the inner tube <NUM> will be described.

<FIG> shows an axially orthogonal cross-section of the inner tube <NUM> in the first region <NUM>. <FIG>, <FIG>, <FIG>, and <FIG> show an axially orthogonal cross-section of the inner tube <NUM> in the second region <NUM>. <FIG> shows an axially orthogonal cross-section of the inner tube <NUM> in the third region <NUM>. Note that a part of the configuration is enlarged and shown in the figures (a site surrounded in a dashed-line in the figures).

As shown in the figures, the linear bodies <NUM> project from the inner surface <NUM> of the tubular body <NUM> in the second region <NUM>. In addition, the linear bodies <NUM> less project from the inner surface <NUM> of the tubular body <NUM> in the first region <NUM> than in the second region <NUM>. In addition, the linear bodies <NUM> less project from the inner surface <NUM> of the tubular body <NUM> in the third region <NUM> than in the second region <NUM>. As described above, a reason for adjusting a projection length of the linear body <NUM> in every portion of the inner tube <NUM> is described.

As described above, the contact area between the inner surface <NUM> of the tubular body <NUM> and the guide wire W is decreased in the site in which the linear bodies <NUM> constituting the reinforcing member <NUM> project from the inner surface <NUM> of the tubular body <NUM>, and thus the sliding resistance is decreased. In other words, the sliding resistance of the guide wire W is decreased in the second region <NUM>.

On the other hand, the projection length of the linear bodies <NUM> is shorter in the first region <NUM> and the third region <NUM> than in the second region <NUM>.

When an uneven shape formed of the linear bodies <NUM> is disposed in the vicinity of the distal opening portion 103a of the inner tube <NUM>, and the guide wire W is inserted into the guide wire lumen <NUM>, the guide wire W is likely to be caught on the linear bodies <NUM>, smooth insertion is hindered, or there is possibility that the guide wire W will be folded or bent. Hence, the projection length of the linear bodies <NUM> from the inner surface <NUM> is decreased in the vicinity of the distal opening portion 103a. In other words, the first resin of the tubular body <NUM> and the second resin of the linear bodies <NUM> are more melt-solidified in the first region <NUM> than in the second region <NUM>. Here, the melt-solidifying means melting of at least a part of the first resin and at least a part of the second resin and solidifying of the parts in a mixed state in which the first resin and the second resin are present together. Hence, the bonding strength of the tubular body <NUM> and the reinforcing member <NUM> in the first region <NUM> is higher than the bonding strength of the tubular body <NUM> and the reinforcing member <NUM> in the second region <NUM>.

In addition, when an uneven shape formed of the linear bodies <NUM> is disposed in the vicinity of the proximal opening portion 104a of the inner tube <NUM>, and the guide wire W is pulled outside from the guide wire lumen <NUM>, the guide wire W is likely to be caught on the linear bodies <NUM>, the pulling-out work is hindered, or there is possibility that the guide wire W will be folded or bent. Hence, the projection length of the linear bodies <NUM> from the inner surface <NUM> is also shortened in the vicinity of the proximal opening portion 104a. In other words, the first resin of the tubular body <NUM> and the second resin of the linear bodies <NUM> are more melt-solidified in the third region <NUM> than in the second region <NUM>. Therefore, the bonding strength of the tubular body <NUM> and the reinforcing member <NUM> in the third region <NUM> is higher than the bonding strength of the tubular body <NUM> and the reinforcing member <NUM> in the second region <NUM>.

As shown in <FIG>, <FIG>, and <FIG>, in the inner tube <NUM> according to the embodiment, the linear bodies <NUM> disposed in the first region <NUM> and the third region <NUM> are melted, and thereby a melted portion <NUM> is formed. The linear bodies <NUM> do not have their original shape in the melted portion <NUM>. In addition, the melted portion <NUM> is fused with the tubular body <NUM>. Therefore, the uneven shape and the gap portion <NUM> which are formed of the linear bodies <NUM> are almost not provided in the first region <NUM> and the third region <NUM>. Hence, the inner surface <NUM> of the inner tube <NUM> is a smooth surface with less unevenness in a circumferential direction in the first region <NUM> and the third region <NUM> than in the second region <NUM>.

As described above, the linear bodies <NUM> disposed in the first region <NUM> and the third region <NUM> are melted to the extent that the linear bodies do not have the original shape, and thereby, it is possible to suitably prevent a problem that the guide wire W is caught in the vicinity of the distal opening portion 103a and the proximal opening portion 104a from occurring. However, the projection length of the linear bodies <NUM> in the first region <NUM> and the third region <NUM> is not particularly limited as long as the projection length is shorter than in the second region <NUM>, and it is possible to prevent the problem that the guide wire W is caught or the like from occurring.

As shown in <FIG> and <FIG>, the projection length of the linear body <NUM> from the inner surface <NUM> of the tubular body <NUM> is shortened from the second region <NUM> toward the first region <NUM> on a boundary portion A1 between the first region <NUM> and the second region <NUM>. As described above, the projection length of the linear bodies <NUM> is gradually shortened. In this manner, a significant difference in physical properties between the first region <NUM> and the second region <NUM> due to the reinforcement of the reinforcing member <NUM> is suppressed, and thus the inner tube <NUM> is prevented from being folded or kinked in the vicinity of the boundary portion A1.

As shown in <FIG> and <FIG>, the projection length of the linear body <NUM> from the inner surface <NUM> of the tubular body <NUM> is shortened from the second region <NUM> toward the third region <NUM> on a boundary portion A2 between the second region <NUM> and the third region <NUM>. Similar to the boundary portion A1 between the first region <NUM> and the second region <NUM>, the projection length of the linear bodies <NUM> is gradually shortened. In this manner, a significant difference in physical properties between the second region <NUM> and the third region <NUM> due to the reinforcement of the reinforcing member <NUM> is suppressed, and thus the inner tube <NUM> is prevented from being folded or kinked in the vicinity of the boundary portion A2.

Next, an operation of the balloon catheter <NUM> according to the embodiment will be described.

The balloon catheter <NUM> includes the outer tube <NUM> having a lumen, the inner tube <NUM> that is disposed in the lumen of the outer tube <NUM> and has the guide wire lumen <NUM> through which the guide wire W is insertable, and the balloon <NUM> fixed to the inner tube <NUM> on the distal side and the outer tube <NUM> on the distal side. The proximal portion of the inner tube <NUM> is provided to form the proximal opening portion 104a that communicates with the guide wire lumen <NUM> in the middle of the outer tube <NUM>. The inner tube <NUM> has the tubular body <NUM> made of the first resin and the reinforcing member <NUM> disposed on the inner side of the tubular body <NUM>. The reinforcing member <NUM> is configured of the linear bodies <NUM> including the second resin. The inner tube <NUM> has the first region <NUM> including the distal portion provided with the distal opening portion 103a and the second region <NUM> that is disposed to be closer to the proximal side than the first region <NUM>. The linear bodies <NUM> project from the inner surface <NUM> of the tubular body <NUM> in the second region <NUM> and less project from the inner surface <NUM> of the tubular body <NUM> in the first region <NUM> than in the second region <NUM>.

In addition, the balloon catheter <NUM> includes the outer tube <NUM> having the lumen, the inner tube <NUM> that is disposed in the lumen of the outer tube <NUM> and has the guide wire lumen <NUM> through which the guide wire W is insertable, and the balloon <NUM> fixed to the inner tube <NUM> on the distal side and the outer tube <NUM> on the distal side. The proximal portion of the inner tube <NUM> forms the proximal opening portion 104a that communicates with the guide wire lumen <NUM> in the middle of the outer tube <NUM>. The inner tube <NUM> has the tubular body <NUM> made of the first resin and the reinforcing member <NUM> disposed on the inner side of the tubular body <NUM>. The reinforcing member <NUM> is configured of the linear bodies <NUM> including the second resin. The inner tube <NUM> has the first region <NUM> including the distal portion provided with the distal opening portion 103a and the second region <NUM> that is disposed to be closer to the proximal side than the first region <NUM>. The first resin of the tubular body <NUM> and the second resin of the linear bodies <NUM> are more melt-solidified in the first region <NUM> than in the second region <NUM>.

The balloon catheter <NUM> configured as described above has the kink resistance or tensile strength improved by the reinforcing member <NUM> provided on the inner side of the tubular body <NUM> provided in the inner tube <NUM>. In addition, in the inner tube <NUM> of the balloon catheter <NUM>, the first resin and the second resin are melt-solidified in the first region <NUM> in the vicinity of the distal opening portion 103a. Therefore, the inner circumferential surface of the inner tube <NUM> has little unevenness by the reinforcing member <NUM>, and thus it is possible to prevent the guide wire W from being caught on the reinforcing member <NUM> in the vicinity of the distal opening portion 103a. On the other hand, the sliding resistance of the guide wire W due to the unevenness by the reinforcing member <NUM> is decreased in the second region <NUM> on the proximal side more than in the vicinity of the distal opening portion 103a.

Since the tubular body <NUM> and the reinforcing member <NUM> both include the resin, the tubular body <NUM> and the reinforcing member <NUM> are easily fused together, compared to a case where the reinforcing member <NUM> is formed of metal. Therefore, when an end portion of the inner tube <NUM> is cut and the distal tip <NUM> is attached, there is no need to perform an end-portion treatment for preventing dispersion of an end portion of the reinforcing member <NUM>, and thus it is easy to perform a manufacturing operation. Further, when a portion in the vicinity of the proximal end of the inner tube <NUM> is attached to a connecting opening portion <NUM> formed at a predetermined position of the outer tube <NUM>, there is also no need to perform the end-portion treatment such that the end portion of the reinforcing member <NUM> is not dispersed, and thus it is easy to perform the manufacturing operation.

In addition, the distal tip <NUM> is disposed in the first region <NUM>. Therefore, when the distal end of the balloon catheter <NUM> comes into contact with a biological organ (intravascular wall), it is possible to suitably prevent the biological organ from being damaged or the like.

In addition, the projection length of the linear body <NUM> from the inner surface <NUM> of the tubular body <NUM> is shortened from the second region <NUM> toward the first region <NUM> on the boundary portion A1 between the first region <NUM> and the second region <NUM>. Therefore, a significant difference in physical properties between the first region <NUM> and the second region <NUM> due to the reinforcement of the reinforcing member <NUM> is suppressed, and thus the inner tube <NUM> is prevented from being folded or kinked in the vicinity of the boundary portion A1.

In addition, the inner tube <NUM> has the third region <NUM> that is disposed to be closer to the proximal side than the second region <NUM>, and thus the linear bodies <NUM> less project from the inner surface <NUM> of the tubular body <NUM> in the third region <NUM> than in the second region <NUM>. Therefore, when the guide wire W is pulled outside from the guide wire lumen <NUM> via the proximal opening portion 104a of the inner tube <NUM>, it is possible to prevent the guide wire W from being caught on the linear bodies <NUM>, and thus it is possible to smoothly pull out the guide wire W.

In addition, the projection length of the linear body <NUM> from the inner surface <NUM> of the tubular body <NUM> is shortened from the second region <NUM> toward the third region <NUM> on the boundary portion A2 between the second region <NUM> and the third region <NUM>. Therefore, a significant difference in physical properties between the second region <NUM> and the third region <NUM> due to the reinforcement of the reinforcing member <NUM> is suppressed, and thus the inner tube <NUM> is prevented from being folded or kinked in the vicinity of the boundary portion A2.

In addition, the reinforcing member <NUM> is formed of the plurality of linear bodies <NUM> which are braided. Therefore, the inner tube <NUM> has good kink resistance or tensile strength by the reinforcing member <NUM>.

In addition, the linear body <NUM> is formed of a wire having a circular cross-sectional shape. In this manner, it is possible to decrease the contact area between the reinforcing member <NUM> and the guide wire W that is inserted through the guide wire lumen <NUM>, and thus it is possible to more suitably decrease the sliding resistance.

In addition, the linear bodies <NUM> are formed of only the second resin. In this manner, it is possible to prevent the reinforcing member <NUM> and the guide wire W from scratching against each other when the guide wire W is inserted through the guide wire lumen <NUM>, and it is possible to suitably prevent the guide wire W from being damaged or broken. Further, regarding the inner tube <NUM>, since the tubular body <NUM> and the linear bodies <NUM> are formed of only the resin when a molding process is performed by using a mold or the like, it is possible to adjust the outer diameter, thickness, hardness, or the like by using the fluidity of the resin. Therefore, the inner tube <NUM> is also excellent in processability.

In addition, the outer layer <NUM> is provided to be configured of a resin having a melting point higher than the first resin and is disposed on the outer surface of the tubular body <NUM>. In this manner, when heat is applied from the side of the outer layer <NUM>, it is possible to suitably prevent the reinforcing member <NUM> from receiving an influence of the heat. Further, since it is possible to melt the tubular body <NUM> that is disposed on the outer layer of the reinforcing member <NUM> such that the reinforcing member <NUM> and the outer layer <NUM> are fused together, it is possible to bond the reinforcing member <NUM> to the outer layer <NUM> while the shape of the reinforcing member <NUM> is suitably prevented from being damaged even in a case where the melting point of the outer layer <NUM> approximates the melting point of the reinforcing member <NUM>.

Next, an inner tube <NUM> according to Modification Example <NUM> of the first embodiment will be described with reference to <FIG>. In the description of the modification example, the description of members or the like which have the same functions as those of the members described above is omitted.

As shown in <FIG>, the inner tube <NUM> may not include the outer layer <NUM>. In other words, the inner tube <NUM> can be configured of the tubular body <NUM> made of the first resin and the reinforcing member <NUM>. Even in a case of such a configuration, the tubular body <NUM> and the reinforcing member <NUM> are fused together, and thereby it is possible to decrease the sliding resistance of the guide wire W. In addition, since it is possible to reduce the number of members to the extent that the outer layer <NUM> is not used, it is possible to achieve a decrease in manufacturing costs.

Next, a reinforcing member <NUM> according to Modification Example <NUM> of the first embodiment will be described with reference to <FIG>. In the description of the modification example, the description of members or the like which have the same functions as those of the members described above is omitted.

As shown in <FIG>, linear bodies <NUM> constituting the reinforcing member <NUM> can be configured to have a core material <NUM> made of metal and a second resin <NUM> that covers an outer circumferential surface of the core material <NUM>, for example.

It is possible to use, as metal of the core material <NUM>, various types of metal wires made of stainless steel, tungsten, copper, nickel, titanium, a piano wire, a cobalt-chromium based alloy, a nickel-tungsten based alloy (superelastic alloy), a copper-zinc based alloy, or an amorphous alloy.

It is possible to use, as an example of the second resin <NUM>, a resin exemplified as the second resin that is used in the embodiment described above.

The use of the linear bodies <NUM> having the core material <NUM> made of metal enables an inner tube <NUM> to have still more improved tensile strength. In addition, as shown in <FIG>, a part of the second resin <NUM> is melted, and a site <NUM>, in which the second resin and the inner surface <NUM> of the tubular body <NUM> are fused together, is formed. In this manner, the bonding strength between the linear bodies <NUM> and the tubular body <NUM> is increased. In this manner, since the core material <NUM> is strongly fixed to the tubular body <NUM>, it is possible to suitably prevent a problem that the core material <NUM> is dispersed or the like from occurring.

The linear body <NUM> having a circular cross section is exemplified; however, similarly, a linear body that is formed to have a cross-section with an elliptical or rectangular shape other than the circular shape can also have the core material <NUM>.

As described above, the balloon catheter according to the present invention is described in the embodiment and the plurality of modification examples; however, the present invention is not limited to the configuration described in the embodiment and the modification examples, and it is possible to perform appropriate modifications based on Claims.

For example, the reinforcing member can be configured of coil-shaped linear bodies. A configuration, in which the reinforcing member is configured of the coil-shaped linear bodies, enables the inner tube to have bendability.

For example, the balloon catheter may be configured to be a balloon catheter that is called a so-called over-the-wire type formed to have a guide wire lumen extending from a distal end to a proximal end of a shaft. In a case of the over-the-wire type balloon catheter <NUM>, the projection length of the linear bodies in the vicinity of the distal opening portion is adjusted to be more shortened than in the second region which is positioned on the proximal side, and thereby it is possible to suitably prevent the guide wire from being caught on the linear bodies when the guide wire W is inserted into the guide wire lumen.

In addition, the balloon catheter may have a configuration in which the linear bodies project from the inner surface of the tubular body at least in the second region and less project from the inner surface of the tubular body in the first region than in the second region. It is possible to modify a configuration or the like other than those described in the embodiment. For example, the linear bodies may not be melted in the third region, or the projection length of the linear bodies may not be adjusted based on a relationship with the first region or the second region.

Hereinafter, another embodiment of the present invention will be described with reference to the figures. Note that a dimension ratio in the figures is enlarged depending on the description and the ratio is different from an actual ratio in some cases.

<FIG> are views showing a configuration of every portion of a medical elongated body according to the embodiment, and <FIG> is a view showing a configurational example of a linear body of a reinforcing member according to an embodiment. <FIG> is an enlarged view showing a part of the configuration (a site surrounded in a dashed-line in <FIG>).

With reference to <FIG>, a medical elongated body <NUM> not falling under the scope of the claims is configured to be a catheter for performing a medical treatment, diagnosis, or the like by being inserted into a blood vessel, a bile duct, a trachea, an esophagus, a urethra, or another body lumen or a body-cavity.

As shown in <FIG>, the medical elongated body <NUM> includes an elongated catheter main body <NUM> that can be guided into a living body, a distal tip <NUM> attached to a distal portion <NUM> of the catheter main body <NUM>, and a hub <NUM> interlocked with a proximal portion <NUM> of the catheter main body <NUM>. In addition, the medical elongated body <NUM> includes an anti-kink protector (strain relief) <NUM> in the vicinity of an interlock portion between the catheter main body <NUM> and the hub <NUM>.

In the present specification, a side on which the distal tip <NUM> is disposed in the catheter main body <NUM> is referred to as a distal side, a side on which the hub <NUM> is disposed in the catheter main body <NUM> is referred to as a proximal side, and a direction in which the catheter main body <NUM> extends is referred to as an axial direction.

<FIG> is an enlarged cross-sectional view showing the vicinity of the distal portion <NUM> of the medical elongated body <NUM>, and <FIG> is an enlarged cross-sectional view showing the vicinity of the proximal portion <NUM> of the medical elongated body <NUM>.

As shown in <FIG>, the catheter main body <NUM> is configured to be a flexible tubular member provided with a lumen <NUM> extending in the axial direction, a distal opening portion 103a that communicates with the lumen <NUM>, and the proximal opening portion 104a that communicates with the lumen <NUM>.

The catheter main body <NUM> has a tubular body <NUM>, a reinforcing member <NUM> (refer to <FIG>) that is disposed on an inner surface <NUM> of the tubular body <NUM>, which forms the lumen <NUM> of the catheter main body <NUM>, and an outer layer <NUM> disposed on the outer surface of the tubular body <NUM>.

The tubular body <NUM> has a hollow tubular shape extending in the axial direction of the catheter main body <NUM>. Similar to the tubular body <NUM>, the outer layer <NUM> has a hollow tubular shape extending in the axial direction of the catheter main body <NUM>.

As shown in <FIG> and <FIG>, the reinforcing member <NUM> is formed of the plurality of linear bodies <NUM> which are braided. The reinforcing member <NUM> is provided with a gap portion <NUM> formed between the plurality of linear bodies <NUM>. The reinforcing member <NUM> has a tubular shape extending in the axial direction of the catheter main body <NUM>.

The distal tip <NUM> attached to the catheter main body <NUM> has a tapered shape having an outer diameter decreasing toward the distal side. The distal tip <NUM> has a through-hole <NUM> penetrating the distal tip <NUM> in an axial direction thereof inside. The through-hole <NUM> can guide the medical device such as the guide wire or the like, which is inserted through the lumen <NUM> of the catheter main body <NUM>, to the outside of the catheter main body <NUM>.

For example, the distal tip <NUM> can be configured of a flexible resin member having a heat-shrinkable property. However, the material of the distal tip <NUM> is not particularly limited as long as the distal tip can be fixed to the catheter main body <NUM>. Note that, in a case where the distal tip <NUM> is configured of a resin member, the distal tip <NUM> can be fixed to the catheter main body <NUM> by fusion. As shown in <FIG>, the distal tip <NUM> is fixed in a state in which a proximal surface thereof is in direct contact with a distal surface of the catheter main body <NUM>. However, the fixation of the distal tip <NUM> is not limited thereto. For example, the distal tip <NUM> may be fixed in a state of covering an outer circumference of the distal end of the catheter main body <NUM> or may be fixed in a state of being inserted into the inner side of the distal end of the catheter main body <NUM>.

The hub <NUM> is provided with a port <NUM> functioning as an insertion opening through which the medical device such as the guide wire is inserted into the lumen <NUM> of the catheter main body <NUM> and a wing portion <NUM> that is used for checking an orientation or the like when the medical elongated body <NUM> is operated. The hub <NUM> can be attached to cover an outer circumference of the proximal portion <NUM> of the catheter main body <NUM> by using an adhesive or a fixture (not shown). It is possible to use, as examples of constituent materials of the hub <NUM>, a thermoplastic resin such as polycarbonate, polyamide, polysulfone, or polyarylate.

Next, a structure of the catheter main body <NUM> will be described.

As shown in <FIG>, the tubular body <NUM> is provided with a convex portion <NUM> formed on the inner surface <NUM> of the tubular body <NUM>. The convex portion <NUM> projects from the inner surface <NUM> toward an inner side in a radial direction (an inner side in a radiation direction) so as to penetrate the gap portion <NUM> formed in the reinforcing member <NUM>. Note that, in an example in the figures, axially orthogonal cross-sections of the tubular body <NUM>, the reinforcing member <NUM>, and the outer layer <NUM> have a circular shape; however, the shape is not limited to the circular shape. For example, the cross section may have an elliptical shape, a rectangular shape, or the like.

The tubular body <NUM> is made of the predetermined first resin. In addition, the linear bodies <NUM> are made of the predetermined second resin. The melting point of the first resin is lower than the melting point of the second resin. As shown in <FIG>, the first resin of the tubular body <NUM> is fused with the second resin in a state in which the convex portion <NUM> penetrates the gap portion (mesh) <NUM> constituting the reinforcing member <NUM>.

The reinforcing member <NUM> has a function of increasing the kink resistance or the tensile strength of the catheter main body <NUM> and a function of decreasing the sliding resistance of the various types of medical devices that are inserted through the lumen <NUM> of the catheter main body <NUM>. In addition, in the embodiment, in order to suitably exhibit the function of decreasing the sliding resistance, the reinforcing member <NUM> is formed of a resin having a melting point higher than the first resin of the tubular body <NUM>. When the reinforcing member <NUM> and the tubular body <NUM> are fused together, a part of the tubular body <NUM> is melted, whereas melting of the reinforcing member <NUM> is suppressed. Therefore, the shape of the linear body <NUM> of the reinforcing member <NUM> is maintained. Since a contact area between the medical device and the inner surface <NUM> of the tubular body <NUM> is decreased in a region in which the shape of the linear bodies <NUM> is maintained, and thus the sliding resistance is significantly decreased. Note that, when the reinforcing member <NUM> and the tubular body <NUM> are fused together due to heating from the outer circumference of the tubular body <NUM>, a part of the reinforcing member <NUM> on the side of the tubular body <NUM> may be melted.

For example, the linear body <NUM> can be formed of a wire having a circular cross-sectional shape. It is possible to decrease a contact area between the reinforcing member <NUM> and the medical device that is inserted through the lumen <NUM> of the catheter main body <NUM> by using a circular wire, and thus it is possible to more appropriately decrease the sliding resistance. In addition, the linear body <NUM> can be formed of a wire having an elliptical cross-sectional shape, for example. When the elliptical wires are used, an area of a site in which the wires overlap each other is increased. Therefore, it is possible to increase the stiffness of the reinforcing member <NUM>. Note that the reinforcing member <NUM> can also be formed of wires having a rectangular cross-sectional shape, may be formed by combining the circular, elliptical, and rectangular wires, or can be configured of wires having a cross-section shape other than the exemplified cross-sectional shapes, for example. An outer diameter or the like of the used wire is not particularly limited.

In the embodiment, since the linear bodies <NUM> constituting the reinforcing member <NUM> are formed of only the second resin, it is possible to prevent the reinforcing member <NUM> and the guide wire from scratching against each other when the metal medical device such as the guide wire is inserted through the lumen <NUM> of the catheter main body <NUM>, and it is possible to suitably prevent the guide wire from being damaged or broken. In addition, regarding the catheter main body <NUM>, since the tubular body <NUM> and the linear bodies <NUM> are formed of only the resin when a molding process is performed by using a mold or the like, it is possible to adjust an outer diameter, thickness, hardness, or the like by using fluidity of the resin. Therefore, the catheter main body <NUM> is also excellent in processability.

Similar to the linear bodies <NUM>, the outer layer <NUM> is made of a resin having the melting point higher than that of the first resin of the tubular body <NUM>. For example, the resins exemplified as the resins of the linear bodies <NUM> can be used as the resin of the outer layer <NUM>. However, so long as the rein is a resin having a melting point higher than that of the first resin of the tubular body <NUM>, it is not limited. Similar to the second resin of the linear body <NUM>, it is possible to select any resin depending on a relationship with the material of the tubular body <NUM>.

In order to decrease the contact area between the inner surface <NUM> of the tubular body <NUM> and the medical device, it is preferable that the shape of the convex portion <NUM> or the like is adjusted depending on the thickness of the linear bodies <NUM>. For example, a length d3 (refer to <FIG>) of the convex portion <NUM> of a site penetrating the gap portion <NUM> can be less than twice the thickness of the linear body <NUM> on a cross-section perpendicular to the axial direction of the catheter main body <NUM>. This is because of the following reasons.

As shown in <FIG>, in a portion in which two linear bodies 121a and 121b overlap each other, the thickness of the reinforcing member <NUM> is the sum of dimensions of a thickness (outer diameter) d1 of the linear body 121a and a thickness (outer diameter) d2 of the linear body 121a. Hence, when the length d3 of the convex portion <NUM> of the site penetrating the gap portion <NUM> is less than the sum of the dimensions of both of the linear bodies 121a and 121b (less than twice the thickness of the linear body <NUM>), it is possible to prevent the convex portion <NUM> from projecting to the inner side in the radial direction more than the gap portion <NUM>, and it is possible to suitably decrease the sliding resistance that acts between the medical device and the inner surface <NUM> of the tubular body <NUM>. Note that, similarly, even when the linear bodies <NUM> have a cross-sectional shape other than the circular cross-sectional shape, the length d3 of the convex portion <NUM> of the site penetrating the gap portion <NUM> is shorter than the total of the thickness dimensions of the braided sites, and thereby it is possible to suitably decrease the sliding resistance.

<FIG> is a view showing a cross-section of a site in which adjacent linear bodies 121a and 121b intersect each other (a cross-sectional view taken along line 12B-12B shown in <FIG>). In the site in which the plurality of linear bodies 121a and 121b intersect each other, at least one linear body 121b has a recessed shape. When heat is applied in order to fuse the tubular body <NUM> and the reinforcing member <NUM> in a state in which the linear bodies 121a and 121b are braided with each other, stress is concentrated on a contact site, and a concave portion <NUM> is formed by receiving an influence of the heat. When the concave portion <NUM> is formed, the linear bodies 121a and 121b are strongly caught on each other. Therefore, it is possible to still better maintain the tubular shape of the reinforcing member <NUM>, and thus it is possible to enhance a reinforcing function. Note that <FIG> shows an example in which the concave portion <NUM> is formed only on the one adjacent linear body 121b; however, the concave portion <NUM> may be formed on both of the linear bodies 121a and 121b depending on an applying state of the heat or an applying state of stress or may be formed only on the linear body 121a disposed on the side of the outer surface of the catheter main body <NUM>. In addition, since it is possible to appropriately change a depth, a shape, or the like of the concave portion <NUM> depending on a condition or the like during the fusion, the shape thereof is not limited to the shape shown in the figure. In addition, the linear bodies 121a and 121b are disposed to be orthogonal to each other; however, the disposition is not limited to such disposition, and it is possible to appropriately change an angle of the site (intersecting site) in which the linear bodies <NUM> overlap each other.

As shown in <FIG>, the catheter main body <NUM> has an intermediate portion <NUM> extending between the distal portion <NUM> provided with the distal tip <NUM> and the proximal portion <NUM> provided with the hub <NUM>. In addition, as shown in <FIG>, the linear bodies <NUM> project from the inner surface <NUM> of the tubular body <NUM> in the intermediate portion <NUM>. On the other hand, as shown in <FIG>, the linear bodies <NUM> less project from the inner surface <NUM> of the tubular body <NUM> in the proximal portion <NUM> than in the intermediate portion <NUM>. A reason for adjusting a projection length of the linear body <NUM> in every portion of the catheter main body <NUM> is as follows.

The proximal portion <NUM> of the catheter main body <NUM> is provided with the proximal opening portion 104a which is an entrance used when the medical device is inserted into the lumen <NUM> of the catheter main body <NUM>. For example, when a recessed shape formed of the linear bodies <NUM> is disposed in the vicinity of the proximal opening portion 104a, and the medical device is inserted into the lumen <NUM>, a problem can arise in that the medical device is likely to be caught on the linear bodies <NUM>, smooth insertion is hindered, or the medical device is likely to become damaged. Hence, the projection length of the linear bodies <NUM> from the inner surface <NUM> is shortened in the vicinity of the proximal portion <NUM>. On the other hand, it is preferable that the sliding resistance is decreased to the largest extent in order to make it possible for the medical device to move smoothly in the lumen <NUM> in the intermediate portion <NUM> of the catheter main body <NUM>. Hence, the linear bodies <NUM> disposed in the intermediate portion <NUM> project from the inner surface <NUM> of the tubular body <NUM> toward the inner side in the radial direction such that it is possible to decrease the sliding resistance.

In the catheter main body <NUM>, a melted portion <NUM> formed of the melted linear bodies <NUM> disposed in the proximal portion <NUM> is formed. The linear bodies <NUM> do not have their original shape in the melted portion <NUM>. The melted portion <NUM> is fused with the tubular body <NUM>. As described above, the linear bodies <NUM> disposed in the proximal portion <NUM> are melted to the extent that the linear bodies do not have the original shape, and thus, it is possible to suitably prevent a problem that the medical device, which is inserted from the proximal opening portion 104a, is caught from occurring. Note that the projection length of the linear bodies <NUM> in the proximal portion <NUM> is not particularly limited as long as it is possible to prevent the problem that the medical device is caught or the like from occurring.

Similar to the proximal portion <NUM>, the projection length of the linear bodies <NUM> may be shorter in the distal portion <NUM> than in the intermediate portion <NUM> of the catheter main body <NUM>. Even in a case of such a configuration, when the medical device is inserted into the lumen <NUM> via the distal opening portion 103a, it is possible to suitably prevent the medical device from being caught on the linear bodies <NUM>. In addition, similar to the proximal portion <NUM>, the melted portion <NUM>, in which the linear bodies <NUM> are melted, may be formed in the distal portion <NUM>. For example, in a case where the distal tip <NUM> is attached to the catheter main body <NUM> by fusion, it is possible to form the melted portion <NUM> when the distal tip <NUM> is attached.

As described above, the medical elongated body <NUM> includes the elongated catheter main body <NUM>. When the catheter main body <NUM> has the tubular body <NUM> made of the first resin and the reinforcing member <NUM> disposed on the inner surface <NUM> of the tubular body <NUM>, which forms the lumen <NUM> of the catheter main body <NUM>. The reinforcing member <NUM> is formed of the plurality of linear bodies <NUM> which are braided and has the gap portion <NUM> between the plurality of linear bodies <NUM> which are braided. The tubular body <NUM> has the convex portion <NUM> that penetrates the gap portion <NUM> on the inner surface <NUM> of the tubular body <NUM>. In the linear body <NUM>, at least an outer circumferential surface of the linear body <NUM> is formed of the second resin. The first resin is fused with the second resin in a state in which the convex portion <NUM> penetrates the gap portion <NUM>. The melting point of the first resin is lower than the melting point of the second resin.

The medical elongated body <NUM> configured as described above has the kink resistance or tensile strength improved by the reinforcing member <NUM> provided on the inner surface <NUM> of the tubular body <NUM>. In addition, when the medical device is inserted into the lumen <NUM> of the catheter main body <NUM>, the contact area between the inner surface <NUM> of the tubular body <NUM> and the medical device is decreased due to the reinforcing member (braided linear bodies <NUM>) <NUM> disposed on the inner surface <NUM> of the tubular body <NUM>. Therefore, the medical device that is inserted into the lumen <NUM> of the catheter main body <NUM> has a low sliding resistance against the inner surface <NUM> of the tubular body <NUM>.

Since the tubular body <NUM> and the reinforcing member <NUM> both include the resin, the tubular body <NUM> and the reinforcing member <NUM> are easily fused together, compared to a case where the reinforcing member <NUM> is formed of metal. Further, since the convex portion <NUM> made of the first resin penetrates the gap portion <NUM> of the second resin of which the reinforcing member <NUM> is configured, and the convex portion is fused therein, a contact area between the first resin and the second resin increases, and thus it is possible to achieve strong fusion between the tubular body <NUM> and the reinforcing member <NUM>.

In addition, the melting point of the first resin of the tubular body <NUM> is lower than the melting point of the second resin included in the reinforcing member <NUM>. Therefore, when the reinforcing member <NUM> is disposed in the tubular body <NUM>, the reinforcing member <NUM> is not melted due to the heat of fusion of the first resin and the second resin, but it is possible to maintain a shape of the reinforcing member <NUM>. In this manner, it is possible to more suitably exhibit a function of reducing the sliding resistance of the medical device.

Since the reinforcing member <NUM> includes the second resin, the reinforcing member <NUM> and the tubular body <NUM> are well fused together. Therefore, when the end portion of the catheter main body <NUM> is cut and the distal tip <NUM> or the hub <NUM> is attached, there is no need to perform the end-portion treatment for preventing dispersion of the end portion of the reinforcing member <NUM>, and thus it is easy to perform the manufacturing operation.

In addition, a length of the convex portion <NUM> of a site penetrating the gap portion <NUM> can be less than twice the thickness of the linear body <NUM> on the cross section perpendicular to the axial direction of the catheter main body <NUM>. In this manner, it is possible to prevent the convex portion <NUM> from projecting more than the gap portion <NUM> to the inner side in the radial direction, and it is possible to suitably decrease the sliding resistance that acts between the inner surface <NUM> of the tubular body <NUM> and the medical device.

In addition, the linear body <NUM> is formed of a wire having a circular cross-sectional shape. In this manner, it is possible to decrease the contact area between the reinforcing member <NUM> and the medical device that is inserted through the lumen <NUM> of the catheter main body <NUM>, and thus it is possible to more suitably decrease the sliding resistance.

In addition, the linear bodies <NUM> are formed of only the second resin. In this manner, it is possible to prevent the reinforcing member <NUM> and the guide wire from being scratched against each other when the metal medical device such as the guide wire is inserted through the lumen <NUM> of the catheter main body <NUM>, and it is possible to suitably prevent the guide wire W from being damaged or broken. Further, regarding the catheter main body <NUM>, since the tubular body <NUM> and the linear bodies <NUM> are formed of only the resin when a molding process is performed by using a mold or the like, it is possible to adjust the outer diameter, thickness, hardness, or the like by using fluidity of the resin. Therefore, the catheter main body <NUM> is also excellent in processability.

In addition, the reinforcing member <NUM> includes at least one of the linear bodies which is recessed in a site where the plurality of linear bodies 121a and 121b intersect each other. In this manner, since the linear bodies 121a and 121b are strongly caught on each other, it is possible to still better maintain the tubular shape of the reinforcing member <NUM>.

In addition, the catheter main body <NUM> has a hub <NUM> that holds the proximal end of the catheter main body <NUM>, the distal portion <NUM> provided with the distal tip <NUM>, the proximal portion <NUM> fixed to the hub <NUM>, and the intermediate portion <NUM> extending between the distal portion <NUM> and the proximal portion <NUM>. The linear bodies <NUM> project from the inner surface <NUM> of the tubular body <NUM> in the second region <NUM> and less project from the inner surface <NUM> of the tubular body <NUM> in the proximal portion <NUM> than in the intermediate portion <NUM>. Therefore, it is possible for the medical device to smoothly move in the intermediate portion <NUM> of the catheter main body <NUM>, and it is possible to suitably prevent the medical device from being caught on the linear bodies <NUM> in the vicinity of the proximal portion <NUM>.

Next, a catheter main body <NUM> according to Modification Example <NUM> of the second embodiment will be described with reference to <FIG>. In the description of the modification example, the description of members or the like which have the same functions as those of the members described above is omitted.

As shown in <FIG>, the catheter main body <NUM> may not include the outer layer <NUM>. In other words, the catheter main body <NUM> can be configured to include the tubular body <NUM> made of the first resin and the reinforcing member <NUM>. Even in a case of such a configuration, a part of the tubular body <NUM> is melted, and the tubular body <NUM> and the reinforcing member <NUM> are fused together. In this manner, it is possible to provide the medical elongated body <NUM> by which it is possible to decrease the sliding resistance that acts between the medical device and the tubular body. In addition, since it is possible to reduce the number of members to the extent that the outer layer <NUM> is not used, it is possible to achieve a decrease in manufacturing costs.

Next, the reinforcing member <NUM> according to Modification Example <NUM> of the second embodiment will be described with reference to <FIG>. In the description of the modification example, the description of members or the like which have the same functions as those of the members described above is omitted.

As shown in <FIG>, the linear bodies <NUM> constituting the reinforcing member <NUM> can be configured to have a core material <NUM> made of metal and a second resin <NUM> that covers an outer circumferential surface of the core material <NUM>, for example.

It is possible to use, as an example of the second resin, a resin exemplified as the second resin that is used in the embodiment described above.

The use of the linear bodies <NUM> having the core material <NUM> made of metal enables a catheter main body <NUM> to have still more improved tensile strength. In addition, as shown in <FIG>, a part of the second resin <NUM> is melted, and a site <NUM>, in which the second resin and the inner surface <NUM> of the tubular body <NUM> are fused together, is formed. In this manner, the bonding strength between the linear bodies <NUM> and the tubular body <NUM> is increased. In this manner, since the core material <NUM> is strongly fixed to the tubular body <NUM>, it is possible to suitably prevent a problem that the core material <NUM> is dispersed or the like from occurring.

As described above, a medical elongated body not falling under the scope of the claims is described in the plurality of modification examples.

For example, the medical elongated body may not be provided with the distal tip or the anti-kink protector. In addition, a special use of the medical elongated body is not particularly limited as long as the medical elongated body can be used for one purpose of guiding the medical device (the guide wire, various types of medical instruments for the medical treatment, or the like) into the living body.

In addition, the medical elongated body may have a configuration in which at least the melting point of the first resin is lower than the melting point of the second resin, and the first resin and the second resin are fused together in a state in which the convex portion of the tubular body penetrates the gap portion of the reinforcing member. It is possible to appropriately modify a configuration or the like other than the configurations described in the embodiments.

In addition, the catheter main body including the tubular body and the reinforcing member described in the second embodiment can be used as the inner tube (inner tube shaft) of the balloon catheter like that described in the first embodiment, for example.

Claim 1:
A balloon catheter (<NUM>) comprising:
an outer tube (<NUM>) having a lumen;
an inner tube (<NUM>, <NUM>, <NUM>) that is disposed in the lumen of the outer tube (<NUM>) and has a guide wire lumen (<NUM>) through which a guide wire (W) is insertable; and
a balloon (<NUM>) fixed on a distal side of the inner tube (<NUM>, <NUM>, <NUM>) and on a distal side of the outer tube (<NUM>),
wherein the inner tube (<NUM>, <NUM>, <NUM>) has a tubular body (<NUM>) made of a first resin and a reinforcing member (<NUM>) disposed on an inner side of the tubular body (<NUM>),
wherein the reinforcing member (<NUM>) is configured of a linear body (<NUM>, 121a, 121b, <NUM>) including a second resin (<NUM>),
wherein the inner tube (<NUM>, <NUM>, <NUM>) has a first region (<NUM>) including a distal portion provided with a distal opening portion (103a) and a second region (<NUM>) that is disposed to be closer to a proximal side than the first region (<NUM>),
characterized in that
a proximal portion of the inner tube (<NUM>, <NUM>, <NUM>) is provided to form a proximal opening portion (104a) formed at the proximal end of the inner tube (<NUM>, <NUM>, <NUM>) that communicates with the guide wire lumen (<NUM>) in the middle of the outer tube (<NUM>), and
that the linear body (<NUM>, 121a, 121b, <NUM>) projects from an inner surface (<NUM>) of the tubular body (<NUM>) in the second region (<NUM>) and less projects from the inner surface (<NUM>) of the tubular body (<NUM>) in the first region (<NUM>) than in the second region (<NUM>).