Catheter

Abstract

A catheter according to the present disclosure comprises: a laser emitter capable of emitting a laser; a tubular member; and an expansion member covering the outside of the tubular member in the radial direction and capable of expanding and contracting in the radial direction. The expansion member is provided with an expansion body part capable of expanding in a cylindrical shape. The tubular member internally defines an insertion space through which the laser emitter can be inserted, the insertion space including a distal opening that opens to the outside of the tubular member and that is on the distal side of the expansion member in the longitudinal direction of the tubular member. The tubular member is provided, on the distal side of the expansion body part in the longitudinal direction, with a check valve that allows the flow of fluid flowing out from the insertion space through the distal opening and that restricts the flow of the fluid from the distal opening into the insertion space.

Description

catheter

[0001] The present disclosure relates to catheters.

[0002] Conventionally, probes that convert laser light into shock waves and utilize the shock wave stress to perform various treatments have been known. Patent Document 1 discloses this type of probe. Also known is a probe that converts the vaporization expansion force of a liquid obtained by spark discharge in a liquid atmosphere into mechanical force to perform treatment. Patent Document 2 discloses this type of probe.

[0003] Japanese Patent Application Laid-Open No. 5-300911 Special Publication No. 2015-522344

[0004] However, the probes described in Patent Documents 1 and 2 still have room for improvement in terms of efficiency in ensuring that the force required for treatment is applied to the target site when treating the target site, such as crushing a calcified area in a blood vessel.

[0005] An object of the present disclosure is to provide a catheter that can improve efficiency when treating a target site.

[0006] A catheter according to a first aspect of the present disclosure is a catheter comprising: (1) a laser emitter capable of emitting a laser; a tubular member; and an expansion member covering the radial outside of the tubular member and capable of expanding and contracting in the radial direction, wherein the expansion member comprises an expansion main body portion that is cylindrically expandable, wherein the tubular member defines an insertion space therein through which the laser emitter can be inserted, the insertion space including a distal opening that opens to the outside of the tubular member on a longitudinally distal side of the tubular member relative to the expansion member, and wherein the tubular member comprises a check valve on the longitudinally distal side of the expansion main body portion that allows a flow of liquid out of the insertion space through the distal opening and regulates a flow of liquid into the insertion space from the distal opening.

[0007] A catheter according to one embodiment of the present disclosure is the catheter described in (1) above, wherein (2) the tubular member comprises a tubular body and a distal tip located distally of the tubular body in the longitudinal direction, the insertion space is partitioned across the tubular body and the distal tip, and the distal opening of the insertion space is formed in the distal tip.

[0008] A catheter according to one embodiment of the present disclosure is: (3) the catheter according to (2) above, wherein the check valve is held between the tubular body and the distal tip.

[0009] A catheter according to one embodiment of the present disclosure is: (4) the catheter according to (2) above, wherein the check valve is held in one of the tubular body and the distal tip.

[0010] A catheter according to one embodiment of the present disclosure is the catheter described in any one of (1) to (4) above, wherein the check valve includes a wire guiding portion that guides a guide wire inserted from the distal opening into the insertion space to allow the guide wire to pass through.

[0011] A catheter according to one embodiment of the present disclosure is (6) a catheter according to any one of (1) to (5) above, wherein the tubular member is covered by the expansion member on the radially inner side relative to the expansion member, and has an inner portion including a laser-transmitting portion that can transmit the laser emitted from the laser emitter located in the insertion space in the radial direction.

[0012] A catheter according to one embodiment of the present disclosure is the catheter described in (6) above, wherein the expansion member has a window portion that can release the laser emitted from the laser emitter located in the insertion space or the pressure wave caused by the laser radially outward.

[0013] A catheter according to one embodiment of the present disclosure is the catheter described in (7) above, wherein the window portion of the expansion member is provided with a shock wave generating portion capable of generating a shock wave as the pressure wave by the laser emitted from the laser emitter.

[0014] A catheter according to one embodiment of the present disclosure is (9) the catheter described in (7) or (8) above, in which the insertion space extends in the longitudinal direction at the position of the inner part of the tubular member so as to include the central axis of the expansion member in an expanded state.

[0015] A catheter according to one embodiment of the present disclosure is a catheter as described in any one of (1) to (9) above, wherein the tubular member defines a branch space therein, proximal to the expansion member in the longitudinal direction, through which a guide wire can be inserted, and which merges with the insertion space.

[0016] A catheter according to one embodiment of the present disclosure is the catheter described in (10) above, wherein the tubular member is provided with a marker that is radiographically or ultrasonically visible at a position in the longitudinal direction where the branch space joins the insertion space.

[0017] A treatment method as a second aspect of the present disclosure is (12) a treatment method including: a preparation step of preparing the catheter described in (1) above; an expansion step of expanding the expansion member of the catheter at a target site; and a treatment step of emitting the laser from the laser emitter toward a shock wave generating unit capable of generating shock waves as pressure waves by the laser emitted from the laser emitter, and treating the target site with the shock waves generated in the shock wave generating unit.

[0018] According to the present disclosure, a catheter can be provided that can improve the efficiency when treating a target site.

[0019] 5 is a diagram showing a catheter according to an embodiment of the present disclosure. FIG. 6 is a cross-sectional view of the catheter taken along line II in FIG. 1. FIG. 7 is a diagram showing a state in which the expansion member of the catheter shown in FIG. 1 is expanded. FIG. 8 is a cross-sectional view of the catheter shown in FIG. 3 at the same position as FIG. 2. FIG. 9 is a cross-sectional view of the catheter shown in FIG. 3 taken along a longitudinal plane, showing a state in which a guide wire is inserted into a position of the insertion space that is covered by the expansion member, but a laser emitter is not inserted therein. FIG. 10 is a cross-sectional view of the catheter similar to FIG. 5, showing a state in which a guide wire is not inserted into a position of the insertion space that is covered by the expansion member, but a laser emitter is inserted therein. FIG. 11 is an enlarged view of the vicinity of the check valve shown in FIG. 12. FIG. 13 is a cross-sectional view of a catheter taken along a longitudinal plane according to an embodiment of the present disclosure. FIG. 14 is an explanatory view for explaining the principle of generation of laser-induced shock waves. FIG. 15 is a flowchart showing a treatment method according to an embodiment of the present disclosure.

[0020] Hereinafter, an embodiment of a catheter according to the present disclosure will be illustrated and described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals.

[0021] [First Embodiment] Fig. 1 is a diagram showing a catheter 1 as one embodiment of a catheter according to the present disclosure. For ease of explanation, Fig. 1 also shows a guidewire GW by a two-dot chain line. Fig. 1 shows the catheter 1 inserted into a blood vessel BV. The catheter 1 is a medical instrument that is inserted into the blood vessel BV and is capable of crushing a calcified region X in the blood vessel BV by utilizing shock waves as pressure waves generated by laser irradiation. The catheter 1 is inserted into the blood vessel BV along the guidewire GW. In this embodiment, the calcified region X in the blood vessel BV is exemplified as a target site to be treated by the catheter 1, but the catheter 1 may also be used to treat other target sites.

[0022] As shown in Fig. 1, the catheter 1 of this embodiment includes a laser emitter 20, a tubular member 2, and an expansion member 3. Fig. 1 shows the catheter 1 percutaneously inserted into a patient's blood vessel BV along a guidewire GW, with the expansion member 3 introduced up to the position of a lesion, which is a target site where a calcified region X has formed. Fig. 1 also shows the expansion member 3 in a contracted state. In the contracted state, the expansion member 3 is guided through the blood vessel BV to the lesion.

[0023] Hereinafter, in the catheter 1, the longitudinal direction of the tubular member 2 will be referred to as the "longitudinal direction A." Furthermore, in the catheter 1, the direction around the axis of the tubular member 2 will be referred to as the "circumferential direction B." Furthermore, in the catheter 1, the radial direction of the tubular member 2, which is the radial direction of an imaginary circle with the tubular member 2 as its central axis in a cross section perpendicular to the longitudinal direction A of the tubular member 2, will be referred to as the "radial direction C." Furthermore, within the longitudinal direction A, the direction from the base end side (hand side) of the catheter 1 manipulated by an operator such as a surgeon toward the tip side of the catheter 1 inserted into a living body will be referred to as the "distal" or "distal side A1," and the direction from the tip side of the catheter 1 toward the base end side of the catheter 1 will be referred to as the "proximal" or "proximal side A2."

[0024] FIG. 2 is a cross-sectional view of the catheter 1 taken along line II in FIG. 1. FIGS. 3 to 5 show the expanded state of the expansion member 3 in the contracted state shown in FIGS. 1 and 2. Specifically, FIG. 3 shows the expanded state of the expansion member 3 in the contracted state shown in FIG. 1 inside the blood vessel BV. FIG. 4 is a cross-sectional view taken at the same position as FIG. 2, showing the expansion member 3 in an expanded state. FIGS. 5 and 6 are cross-sectional views taken along the longitudinal direction A of the catheter 1 in which the expansion member 3 is in an expanded state. FIG. 5 shows a state in which a guidewire GW is inserted through a portion of the insertion space 6 that is covered by the expansion member 3, but the laser emitter 20 is not inserted therethrough. In contrast, FIG. 6 shows a state in which a guidewire GW is not inserted through a portion of the insertion space 6 that is covered by the expansion member 3, but the laser emitter 20 is inserted therethrough.

[0025] 3, the expansion member 3 is positioned at a calcified region X in a blood vessel BV as a target site. Next, the expansion member 3 contacts the calcified region X and expands to apply pressure in the radial direction C.

[0026] 5 and 6 , the tubular member 2 defines an insertion space 6 therein through which a laser emitter 20 capable of emitting a laser can be inserted. The laser emitted from the laser emitter 20 positioned in the insertion space 6 is used to treat a target site via the expansion member 3, as will be described in detail later.

[0027] 5 and 6, the expansion member 3 covers the outside of the tubular member 2 in the radial direction C and is configured to be able to expand and contract in the radial direction C. The expansion member 3 also includes an expansion main body portion 3a1 that is expandable into a cylindrical shape.

[0028] As shown in Figures 5 and 6, the insertion space 6 defined by the tubular member 2 includes a distal opening 6a that opens to the outside of the tubular member 2 on the distal side A1 in the longitudinal direction A relative to the expansion member 3.

[0029] As shown in Figures 5 and 6, the tubular member 2 is provided with a check valve 7 on the distal side A1 in the longitudinal direction A relative to the expandable main body portion 3a1, which allows the flow of liquid out of the insertion space 6 through the distal opening 6a and restricts the flow of liquid into the insertion space 6 from the distal opening 6a.

[0030] As described above, the laser emitter 20 is inserted into the insertion space 6 inside the tubular member 2. The laser emitter 20 is capable of emitting a laser beam while positioned in the insertion space 6. In the catheter 1, the laser emitted from the laser emitter 20 positioned in the insertion space 6 is used to treat the calcified region X in the blood vessel BV, which is the target site, via the expansion member 3 in an expanded state.

[0031] As described above, the insertion space 6 includes a distal opening 6a that opens to the outside of the tubular member 2 on the distal side A1 in the longitudinal direction A with respect to the expansion member 3. Therefore, as shown in Figures 1, 3, and 5, the guidewire GW can be inserted into the insertion space 6 by utilizing the distal opening 6a. That is, the insertion space 6 is used for inserting the guidewire GW in addition to inserting the laser emitter 20.

[0032] However, bodily fluids such as blood may infiltrate the insertion space 6 through the distal opening 6a. If bodily fluids infiltrate the insertion space 6, the laser emitted from the laser emitter 20 located in the insertion space 6 may be refracted in an unintended direction at the interface between the laser and the bodily fluid surrounding the laser emitter 20. For this reason, the tubular member 2 is provided with a check valve 7 to prevent bodily fluids from infiltrating the insertion space 6 at a position where the laser emitter 20 can be located. More specifically, the laser emitter 20 is inserted into the insertion space 6 so that at least a portion of it is located in a region Y in the longitudinal direction A whose outer side in the radial direction C is covered by the expandable main body portion 3a1 of the expansion member 3. For this reason, by arranging the check valve 7 on the distal side A1 in the longitudinal direction A relative to the expandable main body portion 3a1, it is possible to prevent bodily fluids from infiltrating the above-mentioned region Y through the distal opening 6a. This prevents the laser emitted from the laser emitter 20 located in the insertion space 6 from being refracted in an unintended direction by bodily fluid that enters the insertion space 6 from the distal opening 6 a. As a result, the efficiency of treating the target site can be improved.

[0033] The expansion member 3 of this embodiment is capable of emitting pressure waves caused by the laser emitted from the laser emitter 20 outward in the radial direction C. As will be described in detail below, the expansion member 3 of this embodiment is equipped with a shock wave generating unit 40a (see FIG. 6 ) that is capable of generating shock waves as pressure waves by the laser emitted from the laser emitter 20. In the catheter 1 of this embodiment, the laser emitted from the laser emitter 20 located inside the tubular member 2 passes through the laser transmitting portion 2a1 of the tubular member 2 in the radial direction C and is irradiated onto the shock wave generating unit 40a of the expansion member 3. The shock wave generating unit 40a generates shock waves by this laser irradiation and can emit these shock waves outward in the radial direction C.

[0034] However, the configuration is not limited to one in which the expansion member 3 itself generates shock waves. As will be described in detail later, the expansion member 3 may be configured to transmit shock waves generated on the inside of the expansion member 3 in the radial direction C to the outside in the radial direction C, thereby releasing the shock waves to the outside in the radial direction C.

[0035] Furthermore, the expansion member 3 may be configured to transmit the laser emitted from the laser emitter 20 from the inside to the outside in the radial direction C, thereby allowing the laser itself to be emitted outward in the radial direction C. In other words, the catheter according to the present disclosure may be used as a medical device capable of emitting the laser emitted from the laser emitter 20 outward in the radial direction C, for treatment such as photodynamic therapy (PDT) or photoimmunotherapy (PIT).

[0036] The catheter 1 of this embodiment will be described in further detail below with reference to Figures 1 to 7. Figure 7 is an enlarged view of the check valve 7 and its vicinity shown in Figure 6.

[0037] <Laser Emitter 20> As shown in FIGS. 5 and 6, the laser emitter 20 of this embodiment includes a laser emitter main body 21 and a connector portion 22 attached to the proximal end of the laser emitter main body 21.

[0038] The laser emitting body 21 includes a laser emitting section 23 located at its distal end, and a laser non-emitting section 24 connected to the proximal side A2 of the laser emitting section 23.

[0039] The laser emission section 23 in this embodiment is a section of the laser fiber capable of emitting a laser beam that is not covered with a fiber coating layer. In contrast, the non-laser emission section 24 in this embodiment is a section of the laser fiber capable of emitting a laser beam that is covered with a fiber coating layer. The constituent material of the fiber coating layer may be any light-blocking material that can block the laser beam emitted from the laser fiber, and may be, for example, a resin layer such as an ultraviolet-curable resin (UV-curable resin), a metal layer such as a coil, or the like. The fiber coating layer may be a single layer, or multiple layers may be laminated.

[0040] The connector 22 is configured to be connectable to a driving device connected to an optical source. When the connector 22 is connected to the driving device, the laser fiber of the laser emitting main body 21 is optically connected to the driving device. Furthermore, when the connector 22 is connected to the driving device, the driving device is able to drive the laser emitting main body 21 in at least one of the longitudinal direction A and the circumferential direction B.

[0041] The laser emission unit 23 may be configured to emit a laser beam only in a partial region in the circumferential direction B, toward the outside in the radial direction C. In this case, by rotating the laser emission main body 21 in the circumferential direction B using a driving device, the laser beam emitted from the laser emission unit 23 toward the outside in the radial direction C can be emitted over the entire area in the circumferential direction B. The irradiation range L1 (see FIG. 9 ) in the circumferential direction B of the light absorption layer 40 a 3 (see FIG. 6 ) of the extension member 3, onto which the laser beam from the laser emission unit 23 of the laser emitter 20 is irradiated, may be set appropriately. Furthermore, by moving the laser emission main body 21 in the longitudinal direction A while rotating it in the circumferential direction B using a driving device, the laser beam can be emitted from the laser emission unit 23 over the entire area in the circumferential direction B over a predetermined range in the longitudinal direction A. Furthermore, the laser emission unit 23 may be configured to emit a laser beam radially over the entire area in the circumferential direction B. In such a case, by using a driving device to move the laser emitting body 21 in the longitudinal direction A without rotating it in the circumferential direction B, it is possible to emit laser from the laser emitting section 23 over a predetermined range in the longitudinal direction A and over the entire area in the circumferential direction B.

[0042] The laser emitter 20 is inserted into the insertion space 6 inside the tubular member 2. To improve the insertability of the laser emitter 20 through the insertion space 6, the non-laser emission section 24 preferably includes a coating section 24a, the outer surface of which is formed with a hydrophilic coating. The coating section 24a may be, for example, a hydrophilic polymer. Examples of hydrophilic polymers that can be used include cellulose-based polymers, polyethylene oxide-based polymers, maleic anhydride-based polymers (e.g., maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers), acrylamide-based polymers (e.g., polyacrylamide, glycidyl methacrylate-dimethylacrylamide block copolymers), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and derivatives thereof. The coating section 24a may be formed, for example, by dip coating.

[0043] The laser emitter 20 of this embodiment may be configured to emit a laser capable of generating laser-induced shock waves in the light absorption layer 40a3 (see FIG. 6 ), which will be described later, of the expansion member 3 of the catheter 1, and may be configured to emit, for example, a microsecond pulse laser, a nanosecond pulse laser, a picosecond laser, a femtosecond pulse laser, etc. The repetition frequency of the pulse laser emitted from the laser emitter 20 may be, for example, 1 to 500 Hz.

[0044] <Tubular member 2> As shown in Figures 5 and 6, the tubular member 2 of this embodiment includes a check valve 7, a tubular main body 8, and a distal tip 9. The distal tip 9 is located on the distal side A1 of the tubular main body 8 in the longitudinal direction A. The insertion space 6 of this embodiment is defined across the tubular main body 8 and the distal tip 9. A distal opening 6a of the insertion space 6 is formed in the distal tip 9. The check valve 7 of this embodiment is disposed between the tubular main body 8 and the distal tip 9.

[0045] The tubular member 2 of this embodiment also includes an inner portion 2a, a distal end portion 2b, and a main body portion 2c.

[0046] The inner portion 2a is a portion that is covered by the expansion member 3 on the inside in the radial direction C with respect to the expansion member 3. In this embodiment, the inner portion 2a is configured by a tubular main body 8. The inner portion 2a includes a laser transmitting portion 2a1 that can transmit, in the radial direction C, a laser emitted from the laser emitter 20 positioned in the insertion space 6. The laser emitter 20 is inserted into the insertion space 6 so that the laser emitting portion 23 positioned at its distal end is located within the inner portion 2a in the insertion space 6. Therefore, the laser emitted from the laser emitting portion 23 transmits through the laser transmitting portion 2a1 of the inner portion 2a to the outside in the radial direction C.

[0047] The light-transmitting material that makes up the laser transmitting portion 2a1 is not particularly limited as long as it is a material that can transmit the laser from the laser emitter 20, and examples thereof include polymer materials such as polyolefin (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, and mixtures thereof. The laser transmitting portion 2a1 may be transparent in the radial direction C, for example.

[0048] In this embodiment, the inner portion 2a includes a light-shielding portion 2a2 in addition to a laser-transmitting portion 2a1. The laser-transmitting portion 2a1 is a portion of the light-transmitting material that is not covered with a light-shielding material having a lower transmittance than the light-transmitting material. In contrast, the light-shielding portion 2a2 is a portion of the light-transmitting material that is covered with a light-shielding material. The light-shielding material is not particularly limited as long as it has a lower transmittance of the laser from the laser emitter 20 than the light-transmitting material that constitutes the laser-transmitting portion 2a1. Examples of light-shielding materials that can be used include various metal materials such as titanium oxide, barium sulfate, zinc oxide, silver, and aluminum. Furthermore, the light-shielding material may be a resin containing particles of the above-mentioned metal materials, carbon black, or the like.

[0049] The laser transmitting portion 2a1 of the inner portion 2a is formed over the entire area in the circumferential direction B. The laser transmitting portion 2a1 of the inner portion 2a may be formed, for example, over only a part of the inner portion 2a in the longitudinal direction A. In such a case, the remaining part of the inner portion 2a in the longitudinal direction A may be constituted by the light-shielding portion 2a2. Furthermore, the laser transmitting portion 2a1 of the inner portion 2a may be formed, for example, over the entire area of ​​the inner portion 2a in the longitudinal direction A. Therefore, the inner portion 2a may be constituted, for example, by only the laser transmitting portion 2a1.

[0050] As shown in Figures 5 and 6, the insertion space 6 in this embodiment extends in the longitudinal direction A at the position of the inner portion 2a of the tubular member 2 so as to include the central axis O of the expansion member 3 in the expanded state.

[0051] The distal end portion 2b is a portion that is continuous with the inner portion 2a on the distal side A1 in the longitudinal direction A of the expansion member 3. The distal end portion 2b in this embodiment is composed of a tubular body 8 and a distal tip 9.

[0052] The main body portion 2c is a portion that is continuous with the inner portion 2a on the proximal side A2 in the longitudinal direction A of the expansion member 3. The main body portion 2c of this embodiment is constituted by a tubular main body 8.

[0053] The tubular main body 8 of this embodiment includes an inner tube 11 and an outer tube 12 that surrounds the inner tube 11. The insertion space 6 of this embodiment is defined inside the inner tube 11. In addition to the insertion space 6, the tubular main body 8 defines a flow path 10 inside. The flow path 10 is defined between the inner tube 11 and the outer tube 12.

[0054] More specifically, the inner tube 11 of this embodiment includes a distal protruding portion 11a that protrudes toward the distal side A1 from the outer tube 12, a proximal protruding portion 11b that protrudes toward the proximal side A2 from the outer tube 12, and an intermediate portion 11c that connects the distal protruding portion 11a and the proximal protruding portion 11b and whose outer side in the radial direction C is covered by the outer tube 12. The insertion space 6 of this embodiment extends over the distal protruding portion 11a, the proximal protruding portion 11b, and the intermediate portion 11c. The flow path 10 of this embodiment is defined between the intermediate portion 11c of the inner tube 11 and the outer tube 12.

[0055] The expansion member 3 of this embodiment is supported on the outer surface of the tubular member 2. Specifically, the expansion member 3 is supported on the outer surface of the inner tube 11 and the outer surface of the outer tube 12. More specifically, the expansion member 3 of this embodiment is supported across the outer surface of the distal protruding portion 11a of the inner tube 11 and the outer surface of the outer tube main body 12a (described later) of the outer tube 12. As will be described in detail later, the expansion member 3 of this embodiment includes an expansion section 3a that defines a fluid containing space 5 on the inside in the radial direction C and covers the outside of the distal protruding portion 11a of the inner tube 11 in the radial direction C, a distal joint section 3b that is continuous with the distal side A1 of the expansion section 3a and is joined to the outer surface of the distal protruding portion 11a of the inner tube 11, and a proximal joint section 3c that is continuous with the proximal side A2 of the expansion section 3a and is joined to the outer surface of the outer tube main body 12a of the outer tube 12. In other words, the inner portion 2 a of the tubular member 2 in this embodiment is the portion of the inner tube 11 and the outer tube 12 that is covered by the expansion portion 3 a, distal joint portion 3 b, and proximal joint portion 3 c of the expansion member 3.

[0056] The laser emitter 20 can be inserted into the insertion space 6 from the proximal end of the proximal protruding portion 11b. The proximal protruding portion 11b may be provided with a flushing port 11b1 that can inject a liquid such as physiological saline into the insertion space 6. Even if a body fluid such as blood enters the insertion space 6, the body fluid can be pushed out from the distal opening 6a by injecting the flushing liquid from the flushing port 11b1.

[0057] The tubular member 2 of this embodiment defines a branch space 51 therein, through which a guidewire GW can be inserted, which joins with the insertion space 6, on the proximal side A2 in the longitudinal direction A with respect to the expansion member 3. More specifically, the intermediate portion 11c of the inner tube 11 of this embodiment defines the branch space 51. As shown in FIGS. 5 and 6 , the intermediate portion 11c includes an intermediate main body portion 11c1 extending in the longitudinal direction A over the entire area of ​​the intermediate portion 11c and defining the insertion space 6 therein, and a branch portion 11c2 branching off from the intermediate main body portion 11c1 and extending therefrom and defining the branch space 51 therein. A portion of the insertion space 6, on the distal side A1 of the joining portion 50 where the branch space 51 joins, is a dual-purpose insertion space 60a used for inserting the laser emitter 20 and the guidewire GW. In contrast, a portion of the insertion space 6 on the proximal side A2 of the confluence portion 50 where the branch spaces 51 converge is not used for inserting the guidewire GW, but is a dedicated insertion space 60b used for inserting the laser emitter 20. The branch space 51 opens to a side surface of the outer tube 12. However, the branch portion 11c2 that defines the branch space 51 may extend in the longitudinal direction A in parallel with the intermediate main body portion 11c1 and open to the outside at the position of the proximal protrusion 11b.

[0058] In this embodiment, the flow path 10 extends from the fluid supply / discharge port 12b1 formed in the main body 2c of the tubular member 2 to the fluid storage space 5 defined inside the expansion member 3 in the radial direction C. A fluid supply / discharge device such as an indeflator or a syringe can be connected to the fluid supply / discharge port 12b1 via a medical tube or the like. Therefore, a fluid such as a liquid is supplied to the fluid storage space 5 from the fluid supply / discharge device through the flow path 10. When a fluid is supplied to the fluid storage space 5, the expansion member 3 can expand outward in the radial direction C. In contrast, the fluid contained in the fluid storage space 5 is discharged through the flow path 10 to the fluid supply / discharge device. When the fluid is discharged from the fluid storage space 5, the expansion member 3 can contract inward in the radial direction C.

[0059] As described above, the flow path 10 of this embodiment is defined between the inner pipe 11 and the outer pipe 12. Specifically, the flow path 10 of this embodiment is defined between the middle portion 11c of the inner pipe 11 and the outer pipe 12. The fluid supply / discharge port portion 12b1 is formed in the outer pipe 12.

[0060] More specifically, the outer tube 12 of this embodiment includes an outer tube main body 12a and an outer tube hub 12b. The outer tube hub 12b is attached to the proximal side A2 of the outer tube main body 12a. The outer tube hub 12b includes the above-mentioned fluid supply / discharge port 12b1 and proximal end port 12b2. The flow path 10 of this embodiment extends from the fluid supply / discharge port 12b1 of the outer tube hub 12b to the fluid containing space 5.

[0061] The proximal protrusion 11b of the inner tube 11 protrudes from the proximal end opening 12b2 of the outer tube hub 12b toward the proximal side A2. A blocking member 13a made of resin or the like blocks the gap between the outer surface of the intermediate body portion 11c1 of the intermediate portion 11c of the inner tube 11 and the inner surface of the proximal end opening 12b2 of the outer tube hub 12b. The blocking member 13a prevents fluid, such as liquid, flowing through the flow path 10 from leaking from the proximal end opening 12b2. A sealing member 13b, such as an O-ring or X-ring, is provided in the gap between the inner surface of the intermediate body portion 11c1 of the intermediate portion 11c of the inner tube 11 and the outer surface of the laser emitter 20. The sealing member 13b prevents fluid, such as liquid, flowing through the insertion space 6 from leaking from the end of the proximal protrusion 11b of the inner tube 11.

[0062] 5 and 6 , the inner portion 2a of the tubular member 2 is provided with radiopaque markers 14a and 14b that indicate the positions of the distal end and proximal end of the laser transparent portion 2a1. The radiopaque markers 14a and 14b are radiopaque. Specifically, the radiopaque markers 14a and 14b may be formed of, for example, a material that is highly radiopaque. The radiopaque markers 14a and 14b may be formed of, for example, a material that is highly radiopaque, such as platinum, gold, iridium, or tungsten. The radiopaque markers 14a and 14b may be attached, for example, to the outer surface of the distal protrusion 11a of the inner tube 11 of the tubular main body 8. The radiopaque markers 14a and 14b are not limited to being radiopaque and may be, for example, ultrasonically visible.

[0063] As shown in FIG. 5 , the catheter 1 of this embodiment can be moved to a target site along the guidewire GW inserted through the dual-purpose insertion space 60a of the insertion space 6. At this time, the distal end of the laser emitter 20 is located in the dedicated insertion space 60b. The guidewire GW is then retracted to the proximal side A2 from the junction 50. That is, the distal end of the guidewire GW is retracted to the branch space 51. Next, as shown in FIG. 6 , the laser emitter 20 is moved into the dual-purpose insertion space 60a on the distal side A1 from the junction 50, and the laser emitter 23 of the laser emitter 20 is positioned so as to be covered by the expansion member 3. Therefore, it is preferable that the catheter 1 of this embodiment be able to identify the position of the junction 50 located within the living body. It is also preferable that the position of the laser emitter 23 located at the distal end of the laser emitter 20 be able to be identified. That is, the tubular member 2 preferably includes a contrast marker 14c having X-ray contrast at the position of the confluence 50 in the longitudinal direction A. Furthermore, the laser emitter 20 preferably includes a contrast marker 26 having X-ray contrast near the position of the laser emitter 23. By doing so, the operator of the catheter 1, such as a surgeon, can confirm the position of the confluence 50 using the contrast marker 14c during surgery, and can also confirm the position of the laser emitter 23 of the laser emitter 20 using the contrast marker 26. This makes it easier for the operator to operate the laser emitter 20 and the guidewire GW.

[0064] The contrast markers 14c and 26 are configured to have X-ray contrast properties, but are not limited to this and may be configured to have ultrasound visibility, for example.

[0065] The inner tube 11 and the outer tube body 12a of the tubular body 8 of this embodiment are preferably formed of a flexible material, but the material is not particularly limited. Examples of materials for the inner tube 11 and the outer tube body 12a include various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polyimide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based elastomers, and combinations of one or more of these (polymer alloys, polymer blends, laminates, etc.) can also be used.

[0066] The distal tip 9 is connected to the distal end of the tubular body 8 to reduce stress on the biological tissue with which it comes into contact. More specifically, the distal tip 9 is connected to the distal end of the distal protrusion 11a of the inner tube 11 of the tubular body 8. The distal tip 9 defines a through-hole 9a therein that constitutes a portion of the insertion space 6, including the distal opening 6a. More specifically, the distal end of the through-hole 9a is the distal opening 6a.

[0067] The distal end of the distal tip 9 in this embodiment has a tapered shape that narrows toward the distal end. A distal opening 6 a of the insertion space 6 is formed on the distal end surface of the distal tip 9.

[0068] The material of the distal tip 9 may be, for example, the same as the material of the inner tube 11. Furthermore, from the viewpoint of reducing the burden on the biological tissue that comes into contact with the distal tip 9, the material of the distal tip 9 may be a material that is more flexible than the material of the inner tube 11. Specific examples of the material of the distal tip 9 include polyamide elastomer, polyester elastomer, polyurethane elastomer, polyolefin elastomer, fluororesin elastomer, and silicone resin.

[0069] Furthermore, a contrast marker having X-ray contrast properties may be attached to the outer surface of the distal tip 9. However, the contrast marker attached to the distal tip 9 is not limited to a configuration having X-ray contrast properties, and may be a configuration having ultrasound visibility, for example.

[0070] The check valve 7 is located in the insertion space 6. More specifically, the check valve 7 in this embodiment is disposed between the distal end surface of the distal protrusion 11 a of the inner tube 11 of the tubular body 8 and the proximal end surface of the distal tip 9.

[0071] 7, a recess 11a1 is formed in the distal end surface of the tubular main body 8 of this embodiment. More specifically, the recess 11a1 is formed in the distal end surface of the distal protruding portion 11a of the inner tube 11. The check valve 7 of this embodiment is housed in the recess 11a1. That is, the check valve 7 of this embodiment is held in the tubular main body 8 while being housed in the recess 11a1. The distal side A1 of this recess 11a1 is closed by the distal tip 9.

[0072] The check valve 7 of this embodiment is a duckbill valve. Specifically, the check valve 7 of this embodiment includes a cylindrical portion 7a fitted into the recess 11a1 and multiple (two in this embodiment) valve portions 7b protruding from different positions in the circumferential direction B of the cylindrical portion 7a toward the distal side A1. Each of the multiple valve portions 7b is swingable in the radial direction C around a base end connected to the cylindrical portion 7a as a fulcrum. In an unloaded state in which no external force is applied, the multiple valve portions 7b are in contact with each other and close the insertion space 6. In this state, when pressure acts on the multiple valve portions 7b from the proximal side A2 toward the distal side A1 through the insertion space 6, the multiple valve portions 7b swing outward in the radial direction C so as to move away from each other. This opens the insertion space 6. Conversely, when pressure acts on the multiple valve portions 7b from the distal side A1 to the proximal side A2 through the insertion space 6, the multiple valve portions 7b adhere tightly to the inside in the radial direction C, and the insertion space 6 is maintained in a closed state.

[0073] Therefore, even if bodily fluid such as blood enters the insertion space 6 through the distal opening 6a, pressure acts on the multiple valve portions 7b from the distal side A1 to the proximal side A2, so the insertion space 6 remains closed. In other words, the check valve 7 regulates the flow of bodily fluid from the distal side A1 to the proximal side A2 relative to the check valve 7. More specifically, bodily fluid flowing from the distal side A1 to the proximal side A2 relative to the check valve 7 does not pass through the check valve 7.

[0074] In contrast, for example, when body fluid such as blood that has infiltrated a portion of the insertion space 6 that is covered by the expansion member 3 is pushed out through the distal opening 6a, pressure acts on the multiple valve portions 7b from the proximal side A2 to the distal side A1. When this pressure reaches or exceeds a predetermined value that allows the valve portions 7b to swing, the multiple valve portions 7b move away from one another, and the insertion space 6 is opened. In other words, the check valve 7 allows the flow of body fluid from the proximal side A2 to the check valve 7 toward the distal side A1. More specifically, body fluid flowing from the proximal side A2 to the check valve 7 toward the distal side A1 passes through the check valve 7.

[0075] Therefore, for example, when a guidewire GW is inserted into the insertion space 6, even if bodily fluids enter the portion of the insertion space 6 that is covered by the expansion member 3 through a tiny gap between the guidewire GW and the valve portion 7b of the check valve 7, the bodily fluids can be easily pushed out from the distal opening 6a.

[0076] 7, the inner circumferential wall 70 of the recess 11a1 of the tubular main body 8 in which the check valve 7 is housed is provided with a guide surface portion 70a that slopes so that the inner diameter decreases toward the proximal side A2. With such a guide surface portion 70a, the guidewire GW inserted into the insertion space 6 through the distal opening 6a is guided to a position between the multiple valve portions 7b of the check valve 7 while contacting the guide surface portion 70a. Therefore, operability when inserting the guidewire GW into the check valve 7 can be improved.

[0077] 7, the check valve 7 of this embodiment includes a wire guide portion that guides the guidewire GW to allow passage of the guidewire GW inserted from the distal opening 6a into the insertion space 6. More specifically, in the check valve 7 of this embodiment, the distal ends of the multiple valve portions 7b cooperate to form a receiving recess 71 as a wire guide portion that can receive the tip of the guidewire GW inserted from the distal opening 6a into the insertion space 6. Opposing side surface portions 71a1 and 71a2 of the side surface 71a of the receiving recess 71 are inclined so as to approach each other toward the bottom 71b. The bottom 71b of the receiving recess 71 is continuous with the contact portion where the contact surfaces 7b1 of the multiple valve portions 7b are in contact with each other. Therefore, when the tip of the guidewire GW is pushed into the proximal side A2 at the position of the receiving recess 71, the guidewire GW can advance to the proximal side A2 so as to tear apart the contact portions where the contact surfaces 7b1 of the multiple valve portions 7b are in contact with each other. In other words, the provision of the receiving recess 71 can improve the operability when inserting the guidewire GW into the check valve 7.

[0078] The material of which the check valve 7 of this embodiment is made is not particularly limited, but examples thereof include synthetic rubbers such as polybutadiene, nitrile, and chloroprene, natural rubbers such as polyisoprene, thermosetting elastomers such as urethane rubber, silicone rubber, and fluororubber, thermoplastic elastomers, and other elastomers.

[0079] Although the check valve 7 in this embodiment is a duckbill valve having two valve portions 7b, it may also be a duckbill valve having, for example, three or more valve portions. Furthermore, the check valve 7 is not limited to a duckbill valve. The check valve 7 may have any other configuration as long as it allows the flow of liquid out of the insertion space 6 through the distal opening 6a and restricts the flow of liquid into the insertion space 6 from the distal opening 6a. However, from the viewpoint of ease of insertion of the guidewire GW from the distal side A1 to the proximal side A2 and from the viewpoint of simplifying the configuration, it is preferable that the check valve 7 be a duckbill valve as in this embodiment.

[0080] Furthermore, although the check valve 7 in this embodiment is held by the tubular main body 8, the present invention is not limited to this configuration. The check valve 7 may be held by, for example, the distal tip 9. Furthermore, the check valve 7 may be held by the tubular main body 8 and the distal tip 9, for example, by being sandwiched between the tubular main body 8 and the distal tip 9.

[0081] <Expansion member 3> As described above, the expansion member 3 is supported on the outer surface of the tubular member 2. Specifically, the expansion member 3 of this embodiment is supported across the outer surface of the distal protruding portion 11a of the inner tube 11 and the outer surface of the outer tube 12 so as to straddle the distal end of the outer tube 12 in the longitudinal direction A.

[0082] The expansion member 3 in this embodiment is supported on the outer surface of the tubular member 2 in a state in which it surrounds the outside of the tubular member 2 in the radial direction C. In other words, the expansion member 3 surrounds the outside of the outer surface of the tubular member 2 in the radial direction C over the entire area in the circumferential direction B of the tubular member 2.

[0083] The expansion member 3 is configured to be expandable outward in the radial direction C of the tubular member 2. More specifically, the expansion member 3 of this embodiment is configured as an expandable membrane body attached to the outer surface of the tubular member 2. Both ends in the longitudinal direction A of the expandable membrane body serving as the expansion member 3 are annularly joined to the outer surface of the tubular member 2 by adhesive bonding, fusion, or the like, over the entire circumferential direction B of the tubular member 2. More specifically, the distal end of the expandable membrane body serving as the expansion member 3 is annularly joined to the outer surface of the distal protrusion 11a of the inner tube 11 over the entire circumferential direction B. Furthermore, the proximal end of the expandable membrane body serving as the expansion member 3 is annularly joined to the outer surface of the distal end of the outer tube main body 12a of the outer tube 12 over the entire circumferential direction B. The central portion in the longitudinal direction A of the expandable membrane body serving as the expansion member 3 is not joined to the outer surfaces of the inner tube 11 and the outer tube 12 over the entire circumferential direction B of the tubular member 2, and defines an annular fluid storage space 5 between the expandable membrane body and the outer surface of the tubular member 2. When fluid is supplied to the fluid storage space 5 through the flow path 10 of the tubular member 2 described above, the expandable membrane body serving as the expansion member 3 is pressed by the fluid and expands outward in the radial direction C over the entire circumferential direction B.

[0084] As shown in Figure 2, in a contracted state, the expandable membrane body serving as the expansion member 3 is folded and wrapped around the outer surface of the tubular member 2. When fluid is supplied to the fluid storage space 5, the expandable membrane body serving as the expansion member 3 in the contracted state expands, spreading its folds and protruding outward in the radial direction C of the tubular member 2. As a result, as shown in Figures 3 to 6, the expandable membrane body serving as the expansion member 3 enters an expanded state. Conversely, when fluid is discharged from the fluid storage space 5 by suction or the like, the expanded expansion member 3 enters the contracted state shown in Figures 1 and 2.

[0085] The fluid supplied to the fluid containing space 5 may be a gas or a liquid, and examples thereof include gases such as helium gas, CO2 gas, and O2 gas, and liquids such as saline and contrast medium. Furthermore, as will be described in detail later, the fluid supplied to the fluid containing space 5 may be a liquid that can generate a pressure wave due to the laser emitted from the laser emitter 20.

[0086] In this embodiment, the expansion member 3 is configured as an expandable membrane attached to the outer surface of the tubular member 2, but is not limited to this configuration. The expansion member 3 may also be an annular bag supported on the outer surface of the tubular member 2. In other words, the fluid storage space 5 of the expansion member 3 may be a space defined only by the bag that serves as the expansion member 3. In this way, the expansion member 3 may be configured as a balloon that can be expanded and contracted by a fluid, and the expansion member 3 may be configured as an expandable membrane or a bag.

[0087] More specifically, the expansion member 3 of this embodiment includes an expansion section 3a, a distal joint section 3b, and a proximal joint section 3c. The expansion section 3a is expandable in the radial direction C by fluid supplied to the fluid storage space 5. The expansion section 3a of this embodiment includes a cylindrically expandable expansion main body section 3a1, a distal tapered expansion section 3a2 connected to the distal side A1 of the expansion main body section 3a1 and having an expanded diameter in the expanded state that decreases from the proximal side A2 toward the distal side A1 in the longitudinal direction A, and a proximal tapered expansion section 3a3 connected to the proximal side A2 of the expansion main body section 3a1 and having an expanded diameter in the expanded state that decreases from the distal side A1 toward the proximal side A2 in the longitudinal direction A. The distal joint section 3b is connected to the distal side A1 of the distal tapered expansion section 3a2 of the expansion section 3a and is joined to the outer surface of the tubular member 2. Specifically, the distal joint 3b in this embodiment is joined to the outer surface of the distal protruding portion 11a of the inner tube 11 of the tubular member 2. The proximal joint 3c is continuous with the proximal side A2 of the proximal tapered expansion portion 3a3 of the expansion portion 3a, and is joined to the outer surface of the tubular member 2. Specifically, the proximal joint 3c in this embodiment is joined to the outer surface of the distal end portion of the outer tube body 12a of the outer tube 12 of the tubular member 2.

[0088] The expansion member 3 of this embodiment has a window portion 45 that can release pressure waves caused by the laser emitted from the laser emitter 20 located in the insertion space 6 outward in the radial direction C. The window portion 45 of this embodiment is the expansion main body portion 3a1.

[0089] The expansion main body portion 3a1 serving as the window portion 45 of the expansion member 3 of this embodiment is provided with a shock wave generating portion 40a capable of generating shock waves as pressure waves by the laser emitted from the laser emitter 20. The shock wave generating portion 40a will be described in detail below.

[0090] As shown in FIG. 6, in the expansion member 3 of this embodiment, the entire expansion main body portion 3a1 is the shock wave generating portion 40a.

[0091] As shown in FIG. 6 , the expansion body portion 3a1 of the expansion member 3 of this embodiment includes a first transmission layer 40a1 and a second transmission layer 40a2 that are transmissive to the laser emitted from the laser emitter 20 in the radial direction C, and a light-absorbing layer 40a3 that is located outward of the first transmission layer 40a1 and the second transmission layer 40a2 in the radial direction C and is capable of absorbing the laser that has passed through the first transmission layer 40a1 and the second transmission layer 40a2. While the expansion body portion 3a1 of the expansion member 3 of this embodiment includes the first transmission layer 40a1 and the second transmission layer 40a2, this configuration is not limited thereto. The expansion body portion 3a1 of the expansion member 3 may include, for example, only one transmission layer located inward of the light-absorbing layer 40a3 in the radial direction C. Alternatively, the expansion body portion 3a1 of the expansion member 3 may include, for example, three or more transmission layers located inward of the light-absorbing layer 40a3 in the radial direction C.

[0092] Furthermore, in the expansion member 3 of this embodiment, the light absorbing layer 40a3 is the outer surface layer of the expansion main body portion 3a1, but another transparent layer may be laminated on the outer side of the light absorbing layer 40a3 in the radial direction C. However, as in this embodiment, it is preferable that the light absorbing layer 40a3 is the outer surface layer of the expansion main body portion 3a1. In this way, attenuation of laser-induced shock waves due to another transparent layer on the outer side of the light absorbing layer 40a3 in the radial direction C can be suppressed.

[0093] In the expansion main body portion 3a1 of the expansion member 3 of this embodiment, a first transmission layer 40a1, a second transmission layer 40a2, and a light-absorbing layer 40a3 are layered in this order from the inside to the outside in the radial direction C. As a result, as shown in FIG. 9 , the laser emitted from the laser emission portion 23 of the laser emitter 20 housed inside the inner portion 2a of the tubular member 2 passes through the laser transmission portion 2a1, the fluid housed in the fluid storage space 5, and the first transmission layer 40a1 and second transmission layer 40a2 of the expansion main body portion 3a1 of the expansion member 3, and is absorbed by the light-absorbing layer 40a3 of the expansion main body portion 3a1 of the expansion member 3. In the light-absorbing layer 40a3, plasma is generated by the absorbed laser. The plasma generated in the light-absorbing layer 40a3 is easily trapped within the light-absorbing layer 40a3 due to the first transmission layer 40a1 and second transmission layer 40a2 that cover the inside of the light-absorbing layer 40a3 in the radial direction C. This allows laser-induced shock waves to be sent from the light-absorbing layer 40a3 outward in the radial direction C, i.e., toward the outside of the expansion member 3. In other words, the expansion member 3 of this embodiment can emit laser-induced shock waves as pressure waves caused by the laser emitted from the laser emitter 20 outward in the radial direction C. With the catheter 1 of this embodiment, by applying this laser-induced shock wave to the calcified region X in the blood vessel BV, the calcified region X can be fractured.

[0094] Furthermore, the catheter 1 can achieve a state in which the expansion member 3 comes into contact with the calcified region X, which is the target site. Therefore, the above-mentioned laser-induced shock waves can be reliably applied to the calcified region X in the blood vessel BV. In other words, the catheter 1 can ensure the force required for treating the target site by utilizing laser-induced shock waves, and by using the expansion member 3, the laser-induced shock waves can be reliably applied to the target site.

[0095] The first transparent layer 40a1 and the second transparent layer 40a2 of the expansion member 3 may be, for example, transparent resin layers. The second transparent layer 40a2 may be, for example, a base material layer of the expandable membrane body that constitutes the expansion member 3. The first transparent layer 40a1 may be, for example, an inner surface layer that constitutes the inner surface in the radial direction C of the expandable membrane body that constitutes the expansion member 3. The inner surface layer serving as the first transparent layer 40a1 may be arranged to provide protection, flexibility, etc. to the inner surface of the expandable membrane body.

[0096] However, the first transmission layer 40a1 and the second transmission layer 40a2 of the expansion member 3 are not particularly limited in their configuration, as long as they are capable of transmitting the laser irradiated from the laser emitter 20. Examples of materials that can be used to form the first transmission layer 40a1 and the second transmission layer 40a2 include polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyesters such as polyethylene terephthalate, thermoplastic resins such as polyvinyl chloride, ethylene-vinyl acetate copolymers, cross-linked ethylene-vinyl acetate copolymers, and polyurethanes, and polyamides. The total thickness of the one or more transmission layers (the thickness of the two layers, the first transmission layer 40a1 and the second transmission layer 40a2 in this embodiment) can be, for example, 1 to 500 μm. However, the total thickness of the one or more transmission layers is preferably 5 to 100 μm, and more preferably 10 to 50 μm.

[0097] The light absorbing layer 40a3 may be, for example, a black rubber layer, a black resin layer, etc. The light absorbing layer 40a3 is an outer surface layer that forms the outer surface of the expandable membrane body that constitutes the expansion member 3 in the radial direction C.

[0098] However, the light-absorbing layer 40a3 may be configured in any manner that can absorb the laser emitted from the laser emitter 20 and transmitted through the first transmission layer 40a1 and the second transmission layer 40a2, and its configuration is not particularly limited. The light-absorbing layer 40a3 may be configured, for example, from natural rubber or synthetic rubber such as EPDM, nitrile, chloroprene, or neoprene, or from a flexible resin containing a black component such as carbon black, carbon nanotubes, carbon nanohorns, or black perylene pigment. The thickness of the light-absorbing layer 40a3 may be, for example, 1 to 500 μm. However, the thickness of the light-absorbing layer 40a3 is preferably 5 to 100 μm, and more preferably 10 to 50 μm.

[0099] At least one of the first transmission layer 40a1 and the second transmission layer 40a2 and the light absorption layer 40a3 preferably extend over the entire area in the circumferential direction B of the tubular member 2. In this way, laser-induced shock waves can be emitted from the light absorption layer 40a3 outward in the radial direction C over a wider area in the circumferential direction B.

[0100] The shock wave generating unit 40a may be, for example, a liquid contained in the fluid containing space 5. Such a liquid may be, for example, a liquid containing a shock wave generating substance. The shock wave generating substance may be, for example, a metal and / or metal alloy having a relatively high melting temperature, such as tungsten, tantalum, molybdenum, niobium, platinum, and / or iridium. The shock wave generating substance may be, for example, magnesium oxide, beryllium oxide, tungsten carbide, titanium nitride, titanium carbonitride, titanium carbide, etc. The shock wave generating substance may be in any form as long as it can be contained together with the liquid in the fluid containing space 5. However, it is preferable that the shock wave generating substance be in the form of fine particles dispersible in the liquid. The fine particles may be, for example, composed solely of the shock wave generating substance. Alternatively, the fine particles may be, for example, a non-shock wave generating substance coated with the shock wave generating substance. Furthermore, the fine particles may be, for example, a mixture of the non-shock wave generating substance and the shock wave generating substance. However, as in this embodiment, the shock wave generating unit 40a is preferably provided in the expansion member 3. In this way, the laser-induced shock waves emitted from the shock wave generator 40a outward in the radial direction C can be applied to the target site, i.e., the calcified region X (see FIG. 1, etc.), without attenuation. The liquid containing the shock wave-generating substance is not limited to the liquid with dispersed fine particles as described above, but may also contain a solution that converts laser light into pressure waves. An example of such a solution is an aqueous solution of indocyanine green and food coloring.

[0101] The shock wave generating unit 40a may be configured to generate shock waves as pressure waves caused by the laser when irradiated with the laser, and to include a direction changing unit that directs the generated shock waves in a direction different from the laser emission direction. The laser emitted from the laser emission unit 23 toward the shock wave generating unit 40a is irradiated onto the direction changing unit of the shock wave generating unit 40a. The direction changing unit of the shock wave generating unit 40a generates shock waves from the irradiated laser and can emit the generated shock waves in a direction different from the laser emission direction so that they act on the target site. Specifically, the direction changing unit of the shock wave generating unit 40a is positioned opposite the laser emission unit 23 in the direction of laser emission from the laser emission unit 23 of the laser emitter 20. As a result, the laser from the laser emission unit 23 of the laser emitter 20 is irradiated onto the direction changing unit of the shock wave generating unit 40a. The position and shape of the direction changing unit of the shock wave generating unit 40a are adjusted so that the generated shock waves reach the target site. Illustratively, the direction changing section of the shock wave generating section 40a may have an inclined surface that is inclined with respect to the emission direction of the laser so that the laser-induced pressure wave is emitted in a direction perpendicular to the emission direction of the laser from the laser emission section 23 (in this embodiment, the radial direction C). More specifically, the emission direction of the laser emitted from the laser emission section 23 of the laser emitter 20 is set to the distal side A1 of the longitudinal direction A, and the direction changing section of the shock wave generating section 40a is disposed on the distal side A1 of the laser emission section 23. The direction changing section of the shock wave generating section 40a has an inclined surface that is inclined with respect to the longitudinal direction A. In this manner, in the direction changing section of the shock wave generating section 40a, shock waves are generated by the laser irradiated from the laser emission section 23, and the inclined surface of the direction changing section allows the generated shock waves to be emitted outward in the radial direction C toward the target site.

[0102] Furthermore, the shock wave generating section 40a of the expansion member 3 is not limited to the configuration of this embodiment as long as it can generate shock waves using the laser emitted from the laser emitter 20 and emit them outward in the radial direction C.

[0103] Furthermore, the expansion main body portion 3a1 serving as the window portion 45 of the expansion member 3 of this embodiment is capable of emitting shock waves as pressure waves caused by the laser emitted from the laser emitter 20, but is not limited to this configuration. The window portion 45 may be capable of emitting the laser itself emitted from the laser emitter 20 outward in the radial direction C, instead of or in addition to pressure waves caused by the laser emitted from the laser emitter 20.

[0104] Second Embodiment Next, a catheter 101 as another embodiment of a catheter according to the present disclosure will be described with reference to Fig. 8. The catheter 101 of this embodiment differs from the catheter 1 described above (see Fig. 5, etc.) in the configuration of the inner tube 111, but has the other configurations in common. Here, only the differences will be described, and a description of the common configuration will be omitted.

[0105] 8, the inner tube 111 of the tubular member 2 of this embodiment includes a distal protruding portion 11a that protrudes toward the distal side A1 from the outer tube 12, a proximal protruding portion 111b that protrudes toward the proximal side A2 from the outer tube 12, and an intermediate portion 111c that is covered on the outside in the radial direction C by the outer tube 12 and connects the distal protruding portion 11a and the proximal protruding portion 111b. The distal protruding portion 11a of this embodiment has the same configuration as that of the first embodiment described above.

[0106] The intermediate portion 111c of this embodiment defines therein a parallel insertion space 6 and a branch space 51. That is, while the intermediate portion 11c (see FIG. 5, etc.) of the inner tube 11 of the first embodiment branches off from the intermediate main body portion 11c1 (see FIG. 5, etc.) that defines the insertion space 6 therein and includes a branch portion 11c2 (see FIG. 5, etc.) that defines the branch space 51 therein, the intermediate portion 111c of the inner tube 111 of this embodiment does not include a branch portion and protrudes from the proximal end opening 12b2 of the outer tube 12 to the proximal side A2.

[0107] In contrast, the proximal protrusion 111b of this embodiment includes a first branch portion 115a and a second branch portion 115b branching from the intermediate portion 111c. The first branch portion 115a defines the insertion space 6 therein but does not define the branch space 51 therein. The second branch portion 115b defines the branch space 51 therein but does not define the insertion space 6 therein. In other words, in the inner tube 111 of this embodiment, the branch space 51 branching from the insertion space 6 at the intermediate portion 111c does not open at the side surface of the outer tube main body 12a of the outer tube 12, but opens at the proximal end surface of the proximal protrusion 111b on the side A2 proximal to the outer tube 12. The first branch portion 115a of the proximal protrusion 111b of this embodiment is provided with a flush port 111b1 into which a liquid such as physiological saline can be injected in order to push bodily fluids such as blood in the insertion space 6 out of the distal opening 6a.

[0108] Thus, the branch space 51 defined inside the inner tube 111 is not limited to the configuration in which the opening on the proximal side A2 is formed on the side surface of the outer tube 12 (see FIG. 5 ). In other words, the catheter according to the present disclosure is not limited to the so-called rapid exchange type catheter 1 shown in FIGS. 1 to 7 , but may be of the so-called over-the-wire type configuration, such as the catheter 101 of this embodiment.

[0109] As shown in FIG. 10, by using a catheter according to the present disclosure, such as those exemplified in the first and second embodiments, a treatment method including the following steps (I) to (III) can be carried out.

[0110] (I) A preparation step S1 of preparing a catheter according to the present disclosure; (II) An expansion step S2 of expanding the expansion member of this catheter at a target site; and (III) A treatment step S3 of emitting a laser from a laser emitter toward a shock wave generating unit capable of generating shock waves as pressure waves by a laser emitted from the laser emitter, and treating the target site with the shock waves generated in the shock wave generating unit.

[0111] In the treatment step S3, the shock waves generated in the shock wave generating section are released from the expansion member, and the shock waves can be reliably applied to the target area that comes into contact with the expansion member.

[0112] The catheter according to the present disclosure is not limited to the specific configurations shown in the above-described embodiments, and various modifications, changes, and combinations are possible without departing from the scope of the claims.

[0113] The present disclosure relates to catheters.

[0114] REFERENCE SIGNS LIST 1, 101: Catheter 2: Tubular member 2a: Inner portion 2a1: Laser-transmitting portion 2a2: Light-shielding portion 2b: Distal end portion 2c: Main body portion 3: Expansion member 3a: Expansion portion 3a1: Expansion main body portion 3a2: Distal tapered expansion portion 3a3: Proximal tapered expansion portion 3b: Distal joint portion 3c: Proximal joint portion 5: Liquid storage space 6: Insertion space 6a: Distal opening 7: Check valve 7a: Cylindrical portion 7b: Valve portion 7b1: Contact surface 8: Tubular body 9: Distal tip 9a: Through hole 10: Flow path 11, 111: Inner tube 11a: Distal protruding portion 11a1: Recess 11b, 111b: Proximal protruding portion 11b1, 111b1: Flushing port 11c, 111c: Intermediate portion 11c1: Intermediate main body portion 11c2: Branching portion 12: Outer tube 12a: Outer tube main body 12b: Outer tube hub 12b1: Fluid supply / discharge port portion 12b2: Proximal end port portion 13a: Closing member 13b: Sealing member 14a, 14b, 14c: Radiopaque marker 20: Laser emitting body 21: Laser emitting main body 22: Connector portion 23: Laser emitting portion 24: Laser non-emitting portion 24a: Coating portion 26: Radiopaque marker 40a: Shock wave generating portion 40a1: First transmitting layer 40a2: Second transmitting layer 40a3: Light absorbing layer 45: Window portion 50: Confluence portion 51: Branching space 60a: Dual-purpose insertion space 60b: Dedicated insertion space 70: Inner peripheral wall 70a: Guide surface portion 71: Receiving recess (an example of a wire guide portion) 71a: Side surface of receiving recess 71a1: Opposite side surface of side surface of receiving recess 71b: Bottom of receiving recess 115a: First branch portion 115b: Second branch portion A: Longitudinal direction A1: Distal side A2: Proximal side B: Circumferential direction C: Radial direction BV: Blood vessel GW: Guide wire L1: Irradiation region O: Central axis of expansion member X: Calcified region Y: Longitudinal region whose radial outer side is covered by the expansion main body portion of the expansion member

Claims

1. A catheter comprising: a laser emitter capable of emitting a laser; a tubular member; and an expansion member covering the radial outside of the tubular member and capable of expanding and contracting in the radial direction, wherein the expansion member has an expansion main body portion that can be expanded into a cylindrical shape, wherein the tubular member defines an insertion space therein through which the laser emitter can be inserted, the insertion space including a distal opening that opens to the outside of the tubular member on the longitudinally distal side of the tubular member relative to the expansion member, and wherein the tubular member has a check valve on the longitudinally distal side relative to the expansion main body portion that allows the flow of liquid out of the insertion space through the distal opening and regulates the flow of liquid into the insertion space from the distal opening.

2. A catheter according to claim 1, wherein the tubular member comprises a tubular body and a distal tip located distally of the tubular body in the longitudinal direction, the insertion space is partitioned across the tubular body and the distal tip, and the distal opening of the insertion space is formed in the distal tip.

3. The catheter of claim 2, wherein the check valve is held between the tubular body and the distal tip.

4. The catheter of claim 2, wherein the check valve is carried by one of the tubular body and the distal tip.

5. A catheter according to any one of claims 1 to 4, wherein the check valve is provided with a wire guiding portion that guides the guide wire so as to allow passage of the guide wire inserted from the distal opening into the insertion space.

6. A catheter according to any one of claims 1 to 4, wherein the tubular member is covered by the expansion member on the radially inner side relative to the expansion member, and has an inner portion including a laser-transmitting portion that can transmit the laser emitted from the laser emitter located in the insertion space in the radial direction.

7. A catheter as described in claim 6, wherein the expansion member has a window portion that can release the laser emitted from the laser emitter located in the insertion space or the pressure waves caused by the laser outward in the radial direction.

8. A catheter according to claim 7, wherein the window portion of the expansion member is provided with a shock wave generating portion capable of generating shock waves as the pressure waves by the laser emitted from the laser emitter.

9. The catheter according to claim 7, wherein the insertion space extends in the longitudinal direction so as to include the central axis of the expansion member in an expanded state at the position of the inner portion of the tubular member.

10. A catheter as described in any one of claims 1 to 4, wherein the tubular member defines a branch space therein, proximal to the expansion member in the longitudinal direction, through which a guide wire can be inserted, which merges with the insertion space.

11. A catheter according to claim 10, wherein the tubular member is provided with a marker that is radiopaque or ultrasonically visible at a position in the longitudinal direction where the branch space joins the insertion space.

Images