catheter

Abstract

Provided is a balloon catheter comprising: an outer-side tube 11; an inner-side tube 12 which is inserted into a lumen 11a of the outer-side tube 11 and the base-end part of which is bonded to the outer-side tube 11; and a core wire 30 which is inserted into the lumen 11a of the outer-side tube 11 and is extended further toward the leading-end side than the base-end part of the inner-side tube 12. In an overlap range 35 in which the inner-side tube 12 and the core wire 30 overlap in the axial direction, a partition part 37 is disposed at an intermediate position in said axial direction. A hole part 41 through which the inner-side tube 12 is inserted and a hole part 42 through which the core wire 30 is inserted are formed in the partition part 37. The inner-side tube 12 is anchored to the outer-side tube 11 via the partition part 37, and the core wire 30 is not anchored to the partition part 37.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2019-150512, filed on August 20, 2019, the contents of which are incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to catheters. [Background technology]

[0003] Balloon catheters have traditionally been used in treatments such as PTA (percutaneous transluminal angioplasty) and PTCA (percutaneous transluminal coronary angioplasty). A balloon catheter is comprised of an outer tube, an inner tube inserted into the outer tube, and a balloon attached to the distal end of each tube.

[0004] A balloon is attached to the distal end of the outer tube. The inner cavity of the outer tube is a fluid lumen through which a fluid flows, and the balloon is inflated or deflated by passing a compressed fluid through the inner cavity of the outer tube.

[0005] The inner tube is provided in a state in which it extends distally beyond the outer tube, and this extending portion passes through the inside of the balloon and extends distally beyond the balloon. The distal end of the inner tube is joined to the distal end of the balloon. The inner cavity of the inner tube forms a guidewire lumen through which a guidewire is inserted. When the balloon catheter is introduced into the body, the guidewire, which has been introduced into the body beforehand, is inserted into the inner cavity of the inner tube, and the balloon catheter is introduced into the body in this inserted state.

[0006] A known guidewire insertion method is the so-called RX type, in which the guidewire is led out from a midpoint in the axial direction of the outer tube. In an RX type balloon catheter, a guidewire port is formed at a midpoint in the axial direction of the outer tube so as to penetrate the peripheral wall of the outer tube, and the lumen of the inner tube is opened to the outside of the catheter through the guidewire port. In this case, the proximal end of the inner tube is joined to a midpoint in the axial direction of the outer tube, more specifically, to the periphery of the guidewire port. In such an RX type catheter, a guidewire introduced into the inner tube from its distal end is led out of the catheter through the guidewire port.

[0007] Incidentally, a core wire is sometimes provided in an RX-type balloon catheter to increase its rigidity (see, for example, Patent Document 1). The core wire is inserted through the lumen of the outer tube and fixed at its proximal end to a hub. The core wire is also provided, for example, extending distally beyond the guidewire port. In this case, rigidity can be imparted to the distal end of the balloon catheter, improving the force transmission characteristics when the balloon catheter is introduced into the body. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-125897 Summary of the Invention [Problem to be solved by the invention]

[0009] In the above-described configuration in which the core wire extends distally beyond the guidewire port, the core wire and the inner tube are arranged side by side inside (in the lumen of) the outer tube distally beyond the guidewire port. Therefore, when the balloon catheter is introduced into the body, the inner tube may become entangled with the core wire, for example, by wrapping around the core wire. This may result in problems such as reduced guidewire insertion capability through the inner tube.

[0010] This problem is not limited to RX-type balloon catheters, but can also occur in other RX-type catheters.

[0011] The present disclosure has been made in consideration of the above circumstances, and its main object is to provide a catheter that can prevent the inner tube and the core wire from becoming entangled inside the outer tube. [Means for solving the problem]

[0012] In order to solve the above problem, the catheter of the first disclosure is a catheter comprising an outer tube having an internal lumen, an inner tube inserted into the lumen of the outer tube and having a base end joined to a midpoint in the axial direction of the outer tube, and a core wire inserted into the lumen of the outer tube and extending distally beyond the base end of the inner tube, and in the overlapping range where the inner tube and the core wire overlap in the axial direction, a fixing portion for fixing the inner tube or the core wire to the outer tube is provided at a midpoint in the axial direction.

[0013] According to the present disclosure, an inner tube and a core wire are inserted through the lumen of an outer tube. The proximal end of the inner tube is joined to the axial middle of the outer tube, and the core wire extends distally beyond the proximal end of the inner tube. In this case, an overlapping area exists within the interior (lumen) of the outer tube where the inner tube and the core wire overlap in the axial direction.

[0014] In the present disclosure, in such a configuration, a fixing portion for fixing the inner tube or the core wire to the outer tube is provided at the axial center of the overlapping range. In this case, displacement of the inner tube or the core wire inside the outer tube can be suppressed. Therefore, entanglement of the inner tube and the core wire inside the outer tube can be suppressed.

[0015] The catheter of the second disclosure is the catheter of the first disclosure, wherein the fixing portion fixes the inner tube to the outer tube.

[0016] Generally, the core wire has higher rigidity than the inner tube. Therefore, if the core wire is fixed to the outer tube, there is a concern that the catheter's ability to follow the curve of the blood vessel may be reduced when inserted into a curved blood vessel. In this regard, in the present disclosure, the inner tube is fixed to the outer tube, which avoids such concerns and achieves the effects of the first disclosure.

[0017] The catheter of the third disclosure is the catheter of the first or second disclosure, further comprising a partition interposed between the inner tube and the core wire to separate them.

[0018] According to the present disclosure, the inner tube and the core wire are separated by a separating portion interposed therebetween, which further prevents the inner tube and the core wire from becoming entangled.

[0019] The catheter of the fourth disclosure is the catheter of the third disclosure, which includes a wall portion arranged to divide the lumen in the axial direction, and the wall portion is formed with a hole portion through which the inner tube is inserted and a hole portion through which the core wire is inserted, and one of the inner tube and the core wire is fixed to the outer tube via the wall portion which serves as the fixing portion, and the other is not fixed to the wall portion, and the partition portion is formed by the portion of the wall portion between the holes.

[0020] According to the present disclosure, a wall portion is provided to divide the lumen of the outer tube in the axial direction, and the inner tube and the core wire are inserted through holes formed in the wall portion. In this inserted state, one of the inner tube and the core wire is fixed to the outer tube via the wall portion, and the other is not fixed to the wall portion. Furthermore, the portion of the wall portion between the holes is interposed between the inner tube and the core wire and serves as a partition. In this case, the wall portion can be used not only as a fixing portion for fixing one of the inner tube and the core wire, but also as a partition. Therefore, entanglement between the inner tube and the core wire can be suitably suppressed with a relatively simple configuration.

[0021] The catheter of the fifth disclosure is the catheter of the fourth disclosure, wherein the inner tube as one of the inner tube and the core wire is fixed to the outer tube via the wall portion, and the core wire as the other is not fixed to the wall portion.

[0022] According to the present disclosure, the effects of the second disclosure and the fourth disclosure can be obtained at the same time.

[0023] The catheter of the sixth disclosure is the catheter of the fourth or fifth disclosure, wherein the lumen is a fluid lumen through which a fluid flows, and the hole portion has an elongated hole shape.

[0024] According to the present disclosure, the hole provided in the wall portion has an elongated hole shape, so that when the core wire or the inner tube is inserted through the hole, a large non-insertion area of ​​the hole that is not used for insertion can be secured. In this case, when the lumen of the outer tube is used as a fluid lumen through which a fluid flows, the non-insertion area of ​​the hole can be used to pass the fluid. Therefore, there is no need to provide a separate fluid hole in the wall portion for passing the fluid, and the configuration of the wall portion can be simplified.

[0025] The catheter of the seventh disclosure is the catheter of the sixth disclosure, wherein the hole through which the other of the holes that is not fixed to the wall portion is inserted is formed into an elongated hole shape.

[0026] In the fourth disclosure described above, one of the inner tube and the core wire is fixed to the wall, while the other is not fixed to the wall. In this configuration, since one of the inner tube and the core wire needs to be firmly fixed to the wall when inserted into the hole, it is desirable to make the hole shape match the cross-sectional shape of the one of the inner tube and the core wire (e.g., circular). However, since the other is not fixed, there is no need to make the hole shape match that of the one of the inner tube and the core wire. Therefore, in the present disclosure, in consideration of this point, of the holes, (only) the hole through which the other is inserted is made elongated. In this case, it can be a practically preferable configuration for realizing the sixth disclosure described above.

[0027] The catheter of the eighth disclosure is any of the first to seventh disclosures, wherein the core wire has a tapered region at its tip end that is tapered so as to become thinner toward the tip, and the tapered region is arranged to span the entire overlapping range.

[0028] However, if the core wire is thick in the overlapping area where the core wire and the inner tube overlap in the axial direction, the space within the lumen of the outer tube where the inner tube can displace is significantly restricted, and the inner tube must displace along this restricted space. This is thought to make the inner tube more likely to entangle with the core wire. In light of this, the present disclosure provides a tapered region that narrows toward the distal end of the core wire, and this tapered region is positioned over the entire overlapping area between the core wire and the inner tube. In this case, the core wire is thinned in the overlapping area, ensuring the inner tube's degree of freedom of displacement within the outer tube. This makes it less likely for the inner tube to entangle with the core wire. [Brief explanation of the drawings]

[0029] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] 1 is a schematic overall side view showing the configuration of a balloon catheter. [Figure 2] (a) is a longitudinal cross-sectional view showing the configuration of a balloon catheter, (b) is a cross-sectional view taken along line AA in (a), (c) is a cross-sectional view taken along line BB in (a), and (d) is an enlarged view of region C in (a). [Figure 3] FIG. [Figure 4] 10A and 10B are diagrams showing holes provided in a wall portion in another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] An embodiment of the present disclosure will be described below with reference to the drawings. This embodiment relates to a balloon catheter having an inflatable and deflateable balloon. Specifically, the embodiment relates to a balloon catheter for use in PTCA (percutaneous transluminal coronary intervention). The configuration of the balloon catheter will be described below with reference to FIGS. 1 and 2. FIG. 1 is a schematic overall side view showing the configuration of the balloon catheter. FIG. 2 shows (a) a longitudinal cross-sectional view showing the configuration of the balloon catheter, (b) a cross-sectional view taken along line AA of (a), (c) a cross-sectional view taken along line BB of (a), and (d) an enlarged view of region C of (a).

[0031] As shown in FIG. 1, the balloon catheter 10 comprises an outer tube 11, an inner tube 12 inserted into the outer tube 11, a hub 13 attached to the base end (proximal end) of the outer tube 11, and a balloon 14 attached to the tip end (distal end) of each tube 11, 12.

[0032] The outer tube 11 has a lumen 11a (see FIG. 2(a)) extending throughout the axial direction. The lumen 11a corresponds to the "lumen." The outer tube 11 is formed by joining together a plurality of (three in this embodiment) tubes 16-18 aligned in the axial direction. These tubes 16-18 are, in order from the base end, the base end tube 16, the intermediate tube 17, and the distal end tube 18. The base end tube 16 is made of a metal such as a Ni-Ti alloy or stainless steel, and its base end is joined to the hub 13. The intermediate tube 17 is made of a thermoplastic polyamide elastomer and has lower rigidity than the base end tube 16. The distal end tube 18 is made of a thermoplastic polyamide elastomer and has lower rigidity than the intermediate tube 17.

[0033] The inner tube 12 has a lumen 12a (see FIG. 2(a)) extending throughout the axial direction. This lumen 12a is used as a guidewire lumen through which a guidewire G is inserted. The inner tube 12 is inserted into the distal tube 18 of the outer tube 11. The base end of the inner tube 12 is joined to the axially intermediate position of the outer tube 11, specifically to the boundary between the intermediate tube 17 and the distal tube 18.

[0034] In this manner, in the present balloon catheter 10, the inner tube 12 is inserted into the interior (lumen 11a) of the outer tube 11, and these two tubes 11, 12 form a double-tube structure.

[0035] A guidewire port 21 is formed in the outer tube 11 at the joint with the inner tube 12. As shown in FIG. 2(a), the guidewire port 21 is formed so as to penetrate a peripheral wall portion 23 that surrounds the lumen 11a of the outer tube 11. Specifically, the guidewire port 21 is formed in the base end of the distal tube 18 and penetrates the peripheral wall portion 23 of the distal tube 18.

[0036] The proximal end of the inner tube 12 is joined to the periphery of the guidewire port 21 in the outer tube 11 (distal tube 18). In this case, the lumen 12a of the inner tube 12 is opened to the outside of the catheter 10 at its proximal end via the guidewire port 21. This allows the guidewire G introduced into the lumen 12a from the distal opening of the inner tube 12 to be led out of the lumen 12a via the guidewire port 21. In other words, this balloon catheter 10 is an RX-type catheter in which the guidewire G is led out from a midpoint in the axial direction.

[0037] A portion of the inner tube 12 extends distally beyond the outer tube 11, and a balloon 14 is provided to cover the extended region from the outside. The balloon 14 is made of a thermoplastic polyamide elastomer. However, the balloon 14 may also be made of other thermoplastic resins such as polyethylene or polypropylene.

[0038] The base end of the balloon 14 is joined to the distal end of the outer tube 11, and the distal end is joined to the distal end of the inner tube 12. The interior of the balloon 14 is in communication with the hub 13 via the lumen 11a of the outer tube 11, so that compressed fluid supplied via the hub 13 is supplied to the balloon 14 through the lumen 11a. In this case, the lumen 11a serves as a fluid lumen for circulating the compressed fluid. When compressed fluid is supplied to the balloon 14 through the lumen 11a of the outer tube 11, the balloon 14 expands, and when negative pressure is applied to the lumen 11a and the compressed fluid is discharged, the balloon 14 contracts.

[0039] A core wire 30 is provided inside (inner cavity 11a) of outer tube 11. Core wire 30 is provided for the purpose of increasing the rigidity of balloon catheter 10, and the configuration of core wire 30 will be described below with reference to Fig. 2 and Fig. 3. Fig. 3 is a side view showing the configuration of core wire 30.

[0040] 2(a) and 2(b), the core wire 30 is inserted into the lumen 11a of the outer tube 11. The core wire 30 is formed in a linear shape from a metal material, such as stainless steel. The cross section of the core wire 30 (a cross section perpendicular to the axial direction) is circular throughout the axial direction.

[0041] The core wire 30 is fixed at its proximal end to the hub 13. More specifically, only the proximal end of the core wire 30 is fixed, and the entire distal end of the core wire 30 is unfixed. The core wire 30 extends distally beyond the proximal end of the inner tube 12 (in other words, the guidewire port 21), and its distal end is located near the balloon 14. As a result, in the present balloon catheter 10, the core wire 30 imparts rigidity to the vicinity of the balloon 14, improving the transmittance of force when the balloon catheter 10 is introduced into the body.

[0042] As shown in Fig. 3, the core wire 30 becomes thinner toward the distal end. The core wire 30 has a constant region 31 provided on the base end side and a tapered region 32 provided on the distal end side. The constant region 31 has a constant outer diameter (thickness) over the entire axial length, while the tapered region 32 has an outer diameter that continuously decreases from the base end toward the distal end over the entire axial length. Therefore, the tapered region 32 has a tapered shape that becomes thinner toward the distal end.

[0043] More specifically, the tapered region 32 has a plurality of regions 32a, 32b with different taper angles (specifically, the inclination angle of the outer peripheral surface relative to the axial direction). In this embodiment, the base-side region 32a has a steeper taper angle than the tip-side region 32b. Therefore, in this embodiment, the tapered region 32 is tapered in two stages.

[0044] The tapered region 32 does not necessarily have to have a two-stage taper, but may have three or more stages. That is, the tapered region 32 may be formed to have three or more regions with different taper angles. Furthermore, the tapered region 32 may be formed with the same taper angle throughout the entire axial direction.

[0045] 2(a), when the core wire 30 is inserted inside the outer tube 11, the proximal end of the tapered region 32 is located closer to the proximal end than the guidewire port 21. Specifically, the boundary between the regions 32a, 32b of the tapered region 32 is located at approximately the same position as the guidewire port 21 in the axial direction, and more specifically, the boundary is located slightly closer to the distal end than the guidewire port 21.

[0046] In the above-described configuration in which the core wire 30 extends distally beyond the proximal end of the inner tube 12 within the outer tube 11, the extended portion of the core wire 30 is positioned alongside the inner tube 12 within the outer tube 11. In this case, it is anticipated that the inner tube 12 and the core wire 30 will become entangled when the balloon catheter 10 is introduced into the body, which could result in problems such as reduced insertability of the guidewire G through the inner tube 12. In view of this, the present balloon catheter 10 is provided with a unique configuration to prevent entanglement between the inner tube 12 and the core wire 30. This unique configuration will be described below.

[0047] As described above, the core wire 30 extends distally beyond the proximal end of the inner tube 12. In this case, an overlapping region 35 where the core wire 30 and the inner tube 12 overlap in the axial direction exists inside the outer tube 11. The tapered region 32 of the core wire 30 is disposed so as to extend over the entire axial area of ​​this overlapping region 35.

[0048] As shown in Figures 2(c) and (d), the outer tube 11 (specifically, the distal tube 18) is provided with a wall portion 37 that divides the lumen 11a in the axial direction. The wall portion 37 is located at the middle position of the overlapping range 35 in the axial direction. Specifically, the wall portion 37 is located near the center of the overlapping range 35 in the axial direction, and more specifically, is located in the central portion. Only one wall portion 37 is provided on the outer tube 11. Note that in Figure 2(c), the wall portion 37 is shown with dot hatching for convenience.

[0049] The wall portion 37 is formed of the same material as the distal tube 18, that is, thermoplastic polyamide elastomer. The wall portion 37 is a circular plate having substantially the same size as the cross section (circular cross section) of the distal tube 18, and is joined (fixed) to the distal tube 18 by welding (thermal welding) along the entire periphery thereof. In this case, the wall portion 37 is disposed with its thickness direction oriented in the axial direction. The thickness of the wall portion 37 is greater than the thickness of the peripheral wall portion 23 of the outer tube 11. In this embodiment, the thickness of the wall portion 37 is approximately two to three times the thickness of the peripheral wall portion 23. The wall portion 37 does not necessarily have to be joined to the distal tube 18 by welding, and may be joined by other joining methods such as adhesive.

[0050] For manufacturing reasons, the distal tube 18 may be configured to have multiple tube sections that are divided in the axial direction at the same position as the wall section 37. In this case, the distal tube 18 is configured by joining each of these tube sections together by welding or the like.

[0051] The wall portion 37 is formed with a hole 41 through which the inner tube 12 is inserted and a hole 42 through which the core wire 30 is inserted. These holes 41, 42 both penetrate the wall portion 37 in the thickness direction and are arranged side by side in the radial direction of the outer tube 11.

[0052] Of these holes 41, 42, the hole 41 is circular and has the same size as the cross section of the inner tube 12. The inner tube 12 is joined (fixed) to the wall portion 37 by welding (thermal welding) while inserted into this hole 41. In this case, the inner tube 12 is fixed to the outer tube 11 via the wall portion 37 (in other words, by the wall portion 37). Note that in this case, the wall portion 37 corresponds to the fixing portion. Furthermore, the inner tube 12 does not necessarily have to be joined to the wall portion 37 by welding, and may be joined by other joining methods such as adhesive bonding.

[0053] Furthermore, for manufacturing reasons, the inner tube 12 may be configured to have a plurality of tube portions that are divided in the axial direction at the same position as the wall portion 37. In this case, the inner tube 12 is configured by joining each of these tube portions to one another by welding or the like.

[0054] As described above, the inner tube 12 is fixed to the outer tube 11 at its base end, and is fixed to the outer tube 11 at its middle portion via the wall portion 37. The inner tube 12 is fixed to the outer tube 11 only at these two points, and is not fixed to the outer tube 11 in other areas.

[0055] The hole 42 has an elongated hole shape that is long in a direction intersecting the arrangement direction of the holes 41, 42 (more specifically, a direction perpendicular to the arrangement direction). The width (length in the arrangement direction) of the hole 42 is slightly larger than the outer diameter of the core wire 30, and the length (length in the perpendicular direction) is slightly larger than the diameter of the hole 41. As described above, the core wire 30 is inserted through the hole 42. In this case, the core wire 30 is not fixed to the wall 37 in the inserted state. Furthermore, in the inserted state of the core wire 30, a region of the hole 42 where the core wire 30 is not present, i.e., a region not used for inserting the core wire 30, is a non-insertion region. This non-insertion region allows the compressed fluid flowing through the lumen 11a of the outer tube 11 to pass through.

[0056] The portion of the wall 37 between the holes 41, 42 is a partition 45 that separates the holes 41, 42. The partition 45 is interposed between the inner tube 12 inserted through the hole 41 and the core wire 30 inserted through the hole 42. In this case, the partition 45 separates the inner tube 12 and the core wire 30 from each other. The partition 45 corresponds to a partition.

[0057] Next, a brief description will be given of how to use the balloon catheter 10.

[0058] First, a guiding catheter is inserted into a sheath introducer inserted into a blood vessel, and then a guide wire G is inserted into the guiding catheter and introduced to a position beyond the stenotic site.

[0059] Next, the guidewire G is inserted into the lumen 12a of the inner tube 12 of the balloon catheter 10. Then, in this inserted state, the balloon catheter 10 is introduced into the guiding catheter (and thus into the body) along the guidewire G, and the balloon 14 is placed at the stenotic site inside the body.

[0060] As described above, in the present balloon catheter 10, the inner tube 12 is fixed to the outer tube 11 via the wall portion 37. Therefore, when the balloon catheter 10 is introduced into the body, displacement of the inner tube 12 inside the outer tube 11 (lumen 11a) can be suppressed. This prevents the inner tube 12 and the core wire 30 from becoming entangled inside the outer tube 11. This prevents problems such as a decrease in the insertability of the guidewire G through the inner tube 12 or an imbalance in the rigidity of the balloon catheter 10.

[0061] After the balloon 14 is placed at the stricture site, a pressurizer is used to supply compressed fluid to the balloon 14 from the hub 13 side through the lumen 11a of the outer tube 11. This causes the balloon 14 to expand, and the expanded balloon 14 dilates the stricture site.

[0062] As described above, the balloon catheter 10 is primarily inserted into blood vessels and used for treatment inside the blood vessels, but it can also be applied to "tubes" and "body cavities" within the body other than blood vessels, such as the urinary tract and digestive tract.

[0063] According to the configuration of this embodiment described above in detail, the following excellent effects can be obtained.

[0064] In the overlapping area 35 where the inner tube 12 and the core wire 30 overlap, only one of them (specifically, the inner tube 12) is fixed to the outer tube 11, so the other (specifically, the core wire 30) is able to move freely within the outer tube 11. In this case, the aforementioned effect of preventing entanglement of the inner tube 12 and the core wire 30 can be achieved while preventing a decrease in the followability when the balloon catheter 10 is inserted into a curved blood vessel.

[0065] Specifically, of the inner tube 12 and the core wire 30, the core wire 30, which has a higher rigidity, is not fixed to the outer tube 11, and only the inner tube 12, which has a lower rigidity, is fixed to the outer tube 11. In this case, it is possible to suitably suppress a decrease in tracking ability when inserting the balloon catheter 10 into a curved blood vessel.

[0066] A wall 37 is provided to divide the lumen 11a of the outer tube 11 in the axial direction, and a hole 41 through which the inner tube 12 is inserted and a hole 42 through which the core wire 30 is inserted are provided in the wall 37. Of the inner tube 12 and the core wire 30, the inner tube 12 is fixed to the outer tube 11 via the wall 37, while the core wire 30 is not fixed to the wall 37. In this case, a partition 45 between the holes 41, 42 in the wall 37 is interposed between the inner tube 12 and the core wire 30, serving as a partition that separates the inner tube 12 and the core wire 30. As a result, the wall 37 not only fixes the inner tube 12 to the outer tube 11, but also separates the inner tube 12 and the core wire 30 from each other. This further prevents the inner tube 12 and the core wire 30 from becoming entangled. In this case, the wall portion 37 serves both as a fixing portion for fixing the inner tube 12 and as a separating portion for separating the inner tube 12 from the core wire 30, so that the above-mentioned effect can be obtained with a relatively simple configuration.

[0067] Because the hole 42 provided in the wall 37 is shaped like an elongated hole, it is possible to ensure a large non-insertion area in the hole 42 that is not used for insertion when the core wire 30 is inserted through the hole 42. In this case, since the non-insertion area can be used to pass the compressed fluid, there is no need to provide a separate fluid hole in the wall 37 for passing the compressed fluid, and the configuration of the wall 37 can be simplified.

[0068] Of the inner tube 12 and the core wire 30, the inner tube 12 needs to be firmly fixed to the wall 37 while inserted through the hole 41, so it is desirable to make the shape of the hole 41 circular to match the cross-sectional shape of the inner tube 12. In contrast, the core wire 30 is not fixed to the wall 37, so there is no need to make the shape of the hole 42 circular. In view of this, in the above embodiment, of the holes 41, 42, only the hole 42 through which the core wire 30 is inserted is made elongated. In this case, having the hole 41 have an elongated shape, which is a practically preferable configuration for allowing a fluid to pass through.

[0069] A tapered region 32 that narrows toward the tip is provided on the distal end of the core wire 30, and the tapered region 32 is arranged to cover the entire overlapping region 35 between the core wire 30 and the inner tube 12. In this case, the core wire 30 is narrowed in the overlapping region 35, ensuring a degree of freedom of displacement for the inner tube 12 inside the outer tube 11. This makes it difficult for the inner tube 12 to become entangled with the core wire 30.

[0070] The present disclosure is not limited to the above-described embodiment, and may be implemented, for example, as follows.

[0071] (1) In the above embodiment, the inner tube 12 is fixed to the outer tube 11 by the wall portion 37, but the configuration for fixing the inner tube 12 to the outer tube 11 is not necessarily limited to this. For example, the inner tube 12 may be fixed to the outer tube 11 by welding or adhesive. In this case, the welded portion or adhesive layer interposed between the inner tube 12 and the outer tube 11 corresponds to the fixing portion.

[0072] (2) In the above embodiment, the wall portion 37 is disposed in the center of the overlapping range 35, but the wall portion 37 may be disposed on the base end side or the tip end side of the overlapping range 35. Also, in the above embodiment, only one wall portion 37 is provided, but multiple wall portions 37 may be provided at predetermined intervals.

[0073] (3) In the above embodiment, the partition 45 of the wall 37 separates the inner tube 12 and the core wire 30. However, the partition separating the two 12, 30 does not necessarily have to be formed by the wall 37. For example, a linear member extending between the inner tube 12 and the core wire 30 may be provided inside the outer tube 11, and the linear member may serve as the partition. In this case, the linear member may be made of a resin material, and both ends of the linear member may be fixed to the outer tube 11. This configuration may be applied to the configuration described in (1) above, for example. In this case, the partition may be located at the same position as the fixed portion in the axial direction, or at a different position.

[0074] (4) In the above embodiment, the inner tube 12 is fixed to the outer tube 11 by the wall portion 37 of the inner tube 12 and the core wire 30. However, this may be modified so that the core wire 30 is fixed to the outer tube 11 by the wall portion 37. In this case, it is also possible to prevent the inner tube 12 and the core wire 30 from becoming entangled.

[0075] (5) In the above embodiment, of the holes 41, 42 provided in the wall portion 37, the hole 42 is an elongated hole. However, instead of or in addition to this, the hole 41 may be an elongated hole. Even if the hole 41 is an elongated hole, a non-insertion area in the hole 41 where the inner tube 12 is not inserted can be secured, and the non-insertion area can be used to pass a fluid.

[0076] (6) In the above embodiment, the hole 42 is elongated. However, as shown in FIG. 4(a), the hole 42 may be circular (round). In this case, the diameter of the hole 42 is larger than the outer diameter of the core wire 30, thereby ensuring a non-insertion area of ​​the hole 42 where the core wire 30 is not inserted. Therefore, fluid can flow through the non-insertion area. Furthermore, as shown in FIG. 4(b), the wall 37 may be provided with a dedicated hole 47 for passing fluid, in addition to the holes 41 and 42.

[0077] (7) In the above embodiment, the present disclosure is described as being applied to an RX-type balloon catheter, but the present disclosure may also be applied to other RX-type catheters. In other words, the present disclosure can be applied to any RX-type catheter configured such that a core wire is inserted inside an outer tube.

[0078] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0079] 10...balloon catheter, 11...outer tube, 12...inner tube, 14...balloon, 30...core wire, 32...tapered region, 35...overlapping area, 37...wall portion, 41...hole portion, 42...hole portion, 45...partition portion as partition portion.

Claims

1. an outer tube having a lumen through which fluid flows; an inner tube that is inserted into the lumen of the outer tube and has a base end joined to an axially intermediate position of the outer tube; a hub attached to a proximal end of the outer tube; a core wire that is inserted through the lumen of the outer tube, that is fixed at a proximal end to the hub, and that extends distally beyond the proximal end of the inner tube, The outer tube is provided with only one wall portion that divides the lumen in the axial direction, the wall portion is disposed at a middle position in the axial direction within an overlapping range in which the inner tube and the core wire overlap in the axial direction, The wall portion is formed with a hole portion through which the inner tube is inserted and a hole portion through which the core wire is inserted, one of the inner tube and the core wire is fixed to the outer tube via the wall portion, and the other is not fixed to the wall portion; A catheter characterized in that, of the holes, the hole through which the other of the holes not fixed to the wall portion is inserted is formed in an elongated hole shape.

2. the inner tube as one of the inner tube and the core wire is fixed to the outer tube via the wall portion, and the core wire as the other is not fixed to the wall portion, The catheter according to claim 1 , wherein the wall portion is disposed at a central portion of the overlapping area in the axial direction.

3. The core wire has a tapered region formed on its distal end so as to become thinner toward the distal end, 3. The catheter according to claim 1, wherein the tapered region is disposed over the entire overlapping range.

Images