Catheter

Abstract

A catheter according to the present disclosure is provided with a laser emitter, an elongated member, and an expansion member. The elongated member is provided with: an inner portion that is covered by the expansion member and that includes a laser transmission part allowing laser light emitted from the laser emitter to be transmitted therethrough in the radial direction; and a distal end portion that is continuous with the inner portion on the distal side in the longitudinal direction of the elongated member with respect to the expansion member. The expansion member is capable of releasing, outward in the radial direction, the laser light emitted from the laser emitter or pressure waves caused by the laser light. The inner portion of the elongated member defines a first insertion passage that extends in the longitudinal direction so as to include the central axis of the expansion member in an expanded state and through which the laser emitter can be inserted. The distal end portion of the elongated member defines a second insertion passage that extends in the longitudinal direction so as to include the central axis and through which a guide wire can be inserted.

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] JP-A-5-300911 Publication 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 comprises: (1) a laser emitter capable of emitting a laser; an elongated member into which the laser emitter can be inserted; and an expansion member covering the radially outer side of the elongated member and capable of expanding and contracting in the radial direction, wherein the elongated member comprises: an inner portion that is covered by the expansion member on the radially inner side relative to the expansion member and includes a laser transmitting portion that is radially transparent to the laser emitted from the laser emitter; and a distal end portion that is connected to the inner portion on the distal side of the longitudinal direction of the elongated member relative to the expansion member, wherein the expansion member is capable of emitting the laser emitted from the laser emitter or a pressure wave caused by the laser outward in the radial direction, and the inner portion of the elongated member extends in the longitudinal direction so as to include a central axis of the expansion member in an expanded state, and defines a first insertion passage through which the laser emitter can be inserted, The distal end of the elongate member is a catheter that extends in the longitudinal direction so as to include the central axis and defines a second insertion passage through which a guidewire can be inserted.

[0007] A catheter according to one embodiment of the present disclosure is the catheter described in (1) above, wherein (2) the expansion member is provided with a shock wave generating unit capable of generating a shock wave as the pressure wave by the laser emitted from the laser emitter.

[0008] A catheter according to one embodiment of the present disclosure is the catheter described in (1) above, wherein the elongated member is provided with a shock wave generating section capable of generating a shock wave as the pressure wave by the laser emitted from the laser emitter.

[0009] A catheter according to one embodiment of the present disclosure is a catheter according to any one of (1) to (3) above, wherein: (4) the long member has a main body portion connected to the inner portion on the proximal side in the longitudinal direction relative to the expansion member; the first insertion passage and the second insertion passage are not connected in the longitudinal direction; the inner portion of the long member defines a third insertion passage arranged in parallel to the first insertion passage and connected to the second insertion passage; and the main body portion of the long member defines a first communication passage connected to the proximal side in the longitudinal direction of the first insertion passage, and a second communication passage connected to the proximal side in the longitudinal direction of the third insertion passage.

[0010] A catheter according to one embodiment of the present disclosure is a catheter according to any one of (1) to (3) above, wherein: (5) the elongated member has a main body portion connected to the inner portion on the longitudinal proximal side of the expansion member; the first insertion passage and the second insertion passage are connected in the longitudinal direction; and the main body portion of the elongated member partitions a common passage connected to the longitudinal proximal side of the first insertion passage, and a first branch passage and a second branch passage branching from a junction at the longitudinal proximal end of the common passage.

[0011] A catheter according to one embodiment of the present disclosure is the catheter described in (5) above, wherein the main body of the elongated member is provided with a marker that is radiopaque or ultrasonically visible at the position of the longitudinal confluence.

[0012] A catheter according to one embodiment of the present disclosure is (7) the catheter according to any one of (1) to (6) above, wherein the laser emitter comprises: a laser emitting section in which a laser fiber capable of emitting the laser is not covered with a fiber coating layer; and a laser non-emitting section in which the laser fiber is covered with the fiber coating layer.

[0013] A catheter according to one embodiment of the present disclosure is (8) the catheter according to (7) above, in which the non-laser-emitting portion includes a coating portion whose outer surface is formed with a hydrophilic coating.

[0014] A catheter according to one embodiment of the present disclosure is (9) the catheter according to (5) or (6) above, wherein the laser emitter comprises: a laser emitting section in which a laser fiber capable of emitting the laser is not covered with a fiber coating layer; and a laser non-emitting section in which the laser fiber is covered with the fiber coating layer; and the laser emitting section comprises a protective cover that covers the laser fiber and is transparent to the laser.

[0015] A treatment method as a second aspect of the present disclosure is (10) 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 the 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.

[0016] According to the present disclosure, a catheter can be provided that can improve the efficiency when treating a target site.

[0017] 1 is a diagram showing a catheter according to an embodiment of the present disclosure. FIG. 1 is a cross-sectional view of the catheter taken at line II in FIG. 1. FIG. 2 is a diagram showing a state in which an expansion member of the catheter shown in FIG. 1 is expanded. FIG. 3 is a cross-sectional view of the catheter shown in FIG. 3 at the same position as FIG. 2. FIG. 3 is a cross-sectional view of the catheter shown in FIG. 3 taken at a plane along the longitudinal direction. FIG. 4 is a diagram showing a state in which a laser emitter is located in the first insertion passage and a guide wire is inserted in the second insertion passage. FIG. 5 is a diagram showing a state in which a laser emitter is located in the first insertion passage and a guide wire is not inserted in the second insertion passage. FIG. 6 is a cross-sectional view of a catheter according to an embodiment of the present disclosure taken at a plane along the longitudinal direction. FIG. 7 is a cross-sectional view of a catheter according to an embodiment of the present disclosure taken at a plane along the longitudinal direction. FIG. 8 is a diagram showing details of a laser emission unit of the laser emitter of the catheter shown in FIG. 9. FIG. 9 is a cross-sectional view of a catheter according to an embodiment of the present disclosure taken at a plane along the longitudinal direction. FIG. 10 is an explanatory view for explaining the principle of generation of laser-induced shock waves. FIG. 11 is a flowchart showing a treatment method according to an embodiment of the present disclosure. FIG. 12 is a diagram showing a modification of the catheter shown in FIG. 1.

[0018] 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.

[0019] [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.

[0020] As shown in Fig. 1, the catheter 1 of this embodiment includes a laser emitter 20, a long 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.

[0021] Hereinafter, in the catheter 1, the longitudinal direction of the elongated member 2 will be referred to as the "longitudinal direction A." Furthermore, in the catheter 1, the direction around the axis of the elongated member 2 will be referred to as the "circumferential direction B." Furthermore, in the catheter 1, the radial direction of the elongated member 2, which is the radial direction of an imaginary circle with the elongated member 2 as its central axis in a cross section perpendicular to the longitudinal direction A of the elongated 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."

[0022] 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 within 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. Fig. 5 is a cross-sectional view taken along the longitudinal direction A of the catheter 1 in which the expansion member 3 is in an expanded state.

[0023] 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.

[0024] The elongated member 2 is configured so that a laser emitter 20 capable of emitting a laser can be inserted therein. As will be described in detail later, the laser emitted from the laser emitter 20 located inside the elongated member 2 is used to treat the target site via the expansion member 3.

[0025] The expansion member 3 covers the outside of the elongated member 2 in the radial direction C, and is configured to be able to expand and contract in the radial direction C.

[0026] 1 to 5 , the elongated member 2 has an inner portion 2a that is covered by the expansion member 3 on the inner side in the radial direction C relative to the expansion member 3. The inner portion 2a includes a laser transmitting portion 2a1 that can transmit the laser emitted from the laser emitter 20 in the radial direction C.

[0027] As shown in FIGS. 1, 3, and 5, the elongated member 2 has a distal end portion 2b that is continuous with the inner portion 2a on the distal side A1 in the longitudinal direction A relative to the expansion member 3.

[0028] The expansion member 3 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 FIGS. 5 to 6B ) 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 elongated member 2 passes through the laser transmitting portion 2a1 of the inner portion 2a of the elongated 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 is able to emit these shock waves outward in the radial direction C.

[0029] 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.

[0030] 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).

[0031] 5, the inner portion 2a of the elongated member 2 defines a first insertion passage 15 that extends in the longitudinal direction A so as to include the central axis O of the expansion member 3 in the expanded state and through which the laser emitter 20 can be inserted. Also, as shown in FIG. 5, the distal end portion 2b of the elongated member 2 defines a second insertion passage 16 that extends in the longitudinal direction A so as to include the central axis O and through which a guidewire GW (see FIG. 1, etc.) can be inserted.

[0032] In this way, the first insertion passage 15 defined by the inner portion 2 a of the elongated member 2 extends in the longitudinal direction A so as to include the central axis O of the expansion member 3 in the expanded state, and the second insertion passage 16 defined by the distal end portion 2 b of the elongated member 2 extends in the longitudinal direction A so as to include the central axis O of the expansion member 3 in the expanded state, making it easier for the laser emitter 20 located in the first insertion passage 15 to be positioned on the central axis O of the expanded expansion member 3. Therefore, it is possible to suppress variation in the radial direction C of the distance L2 (see FIG. 5 ) from the laser emitter 20 located in the first insertion passage 15 to the expansion member 3 depending on the position in the circumferential direction B. This makes it possible to suppress variation depending on the position in the circumferential direction B in the intensity of the laser emitted from the laser emitter 20 located in the first insertion passage 15 and emitted outward in the radial direction C from the expansion member 3, or in the intensity of the pressure wave generated by the laser emitted from the laser emitter 20 located in the first insertion passage 15 and emitted outward in the radial direction C from the expansion member 3. This makes it possible to improve the efficiency when treating a target site such as a calcified region X in a blood vessel BV.

[0033] 1 to 6B, the catheter 1 of this embodiment will be described in further detail. Fig. 6A shows a state in which the laser emitter 20 is located in the first insertion passage 15 defined by the inner portion 2a of the elongated member 2, and a guidewire GW is inserted into the second insertion passage 16 defined by the distal end portion 2b of the elongated member 2. Fig. 6B shows a state in which the laser emitter 20 is located in the first insertion passage 15 defined by the inner portion 2a of the elongated member 2, and a guidewire GW is not inserted into the second insertion passage 16 defined by the distal end portion 2b of the elongated member 2.

[0034] <Laser Emitter 20> As shown in FIG. 5, 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.

[0035] The laser emitting body 21 comprises a laser emitting section 23 located at its distal end, a drive transmission connector 24 located at its proximal end and covered by a connector section 22, and a long laser non-emitting section 25 extending between the laser emitting section 23 and the drive transmission connector 24.

[0036] The laser emission section 23 in this embodiment is a portion of the laser fiber 31 (see FIGS. 2 and 4) capable of emitting a laser beam that is not covered with the fiber coating layer 32 (see FIGS. 2 and 4). In contrast, the laser non-emission section 25 in this embodiment is a portion of the laser fiber 31 capable of emitting a laser beam that is covered with the fiber coating layer 32. The material of the fiber coating layer 32 may be any light-blocking material that can block the laser beam emitted from the laser fiber 31, 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 32 may be a single layer, or multiple layers may be laminated.

[0037] The connector 22 is configured to be connectable to a drive device connected to an optical source. When the connector 22 is connected to the drive device, the laser fiber 31 is optically connected to the drive device. When the connector 22 is connected to the drive device, the drive device is able to drive the laser emitting body 21 in at least one of the longitudinal direction A and the circumferential direction B via the drive transmission connector 24.

[0038] More specifically, the connector part 22 of this embodiment includes a connector main body 22a connectable to the drive device and an inner cylindrical part 22b protruding from the connector main body 22a toward the distal side A1. The proximal end of the laser emitting main body 21 is fitted and fixed within the inner cylindrical part 22b of the connector part 22. The inner cylindrical part 22b of the connector part 22 of this embodiment includes a flange part 22b1 protruding outward in the radial direction C.

[0039] 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 such a 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. 11 ) in the circumferential direction B of the light absorption layer 40 a 3 (see FIG. 6B ) 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.

[0040] The laser emitter 20 is inserted into the elongated member 2. To improve the insertability of the laser emitter 20 through the elongated member 2, the non-laser emitting section 25 preferably includes a coating section 25a (see FIGS. 2 and 4 ) whose outer surface is formed with a hydrophilic coating. The coating section 25a 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 25a may be formed, for example, by dip coating.

[0041] The laser emitter 20 of this embodiment may be configured to emit a laser capable of generating laser-induced shock waves in a light absorption layer 40a3 (see FIG. 6B ), 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.

[0042] <Long member 2> As shown in Figures 1, 3, and 5 to 6B, the long member 2 of this embodiment has, in addition to the above-mentioned inner portion 2a and distal end portion 2b, a main body portion 2c that is continuous with the inner portion 2a on the proximal side A2 in the longitudinal direction A relative to the expansion member 3.

[0043] 5 to 6B , the first insertion passage 15 and the second insertion passage 16 in this embodiment do not communicate with each other in the longitudinal direction A. Specifically, the distal side A1 of the first insertion passage 15 is closed by a closing wall 15a. In other words, the distal side A1 of the first insertion passage 15 terminates inside the elongated member 2. The closing wall 15a is formed in a region where the inner portion 2a is located in the longitudinal direction A.

[0044] 5 to 6B , the inner portion 2a of the elongated member 2 in this embodiment is arranged in parallel with the first insertion passage 15 and defines a third insertion passage 17 that communicates with the second insertion passage 16. The third insertion passage 17 extends in the longitudinal direction A at a position that does not include the central axis O of the expansion member 3 in the expanded state. The third insertion passage 17 does not communicate with the first insertion passage 15. The third insertion passage 17 also communicates with the second insertion passage 16 at a position A1 distal to the closure wall 15a.

[0045] The main body 2c also defines a first communication passage 18 communicating with the proximal side A2 of the first insertion passage 15 in the longitudinal direction A, and a second communication passage 19 communicating with the proximal side A2 of the third insertion passage 17 in the longitudinal direction A. Specifically, the first insertion passage 15 and the first communication passage 18 are coaxially connected, and the third insertion passage 17 and the second communication passage 19 are coaxially connected. The first communication passage 18 and the second communication passage 19 are not connected.

[0046] That is, the elongated member 2 of this embodiment defines a first lumen 4a, through which the laser emitter 20 can be inserted, including the first insertion passage 15 and the first communication passage 18. The elongated member 2 of this embodiment also defines a second lumen 4b, through which the guidewire GW (see FIG. 1 , etc.) can be inserted, including the second insertion passage 16, the third insertion passage 17, and the second communication passage 19.

[0047] As described above, in this embodiment, the first insertion passage 15 and the second insertion passage 16 are not in communication with each other, but this is not limiting. The first insertion passage 15 and the second insertion passage 16 may be in communication with each other (see FIGS. 8 and 10).

[0048] Furthermore, in addition to the first lumen 4a and second lumen 4b described above, the elongated member 2 of this embodiment defines a third lumen 4c therein through which the fluid supplied to the fluid storage space 5 defined by the expansion member 3 can flow. The elongated member 2 of this embodiment defines the first lumen 4a, the second lumen 4b, and the third lumen 4c separately therein.

[0049] 5 to 6B , the laser emitter 20 is inserted into the first lumen 4a until the laser emitter 23 located at its distal end is positioned in the first insertion passage 15. The inner portion 2a defining the first insertion passage 15 is provided with a laser transmitting portion 2a1 that allows the laser emitted from the laser emitter 23 of the laser emitter 20 to transmit in the radial direction C. Therefore, the laser emitted from the laser emitter 23 located in the first insertion passage 15 transmits outward in the radial direction C through the laser transmitting portion 2a1 of the inner portion 2a.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The elongated member 2 of this embodiment includes an inner tube 11 and an outer tube 12 that surrounds the inner tube 11. The longitudinal direction A of the elongated member 2 of this embodiment is the longitudinal direction of the inner tube 11 and the outer tube 12. The first lumen 4a and the second lumen 4b of this embodiment are separately defined inside the inner tube 11. The third lumen 4c of this embodiment 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 surface in the radial direction C is covered by the outer tube 12. The first lumen 4a of this embodiment extends across the distal protruding portion 11a, the proximal protruding portion 11b, and the intermediate portion 11c. The second lumen 4b of this embodiment extends across the distal protruding portion 11a and the intermediate portion 11c. The proximal end of the second lumen 4b opens into the side surface of the outer tube 12 at the position of the intermediate portion 11c of the inner tube 11. The third lumen 4c of this embodiment is defined between the intermediate portion 11c of the inner tube 11 and the outer tube 12.

[0055] 5 , the proximal protruding portion 11b of the inner tube 11 of this embodiment includes a holding portion 51 that holds the laser emitter 20 inserted into the first lumen 4a so that the laser emitter 20 is relatively movable in the longitudinal direction A. Specifically, the holding portion 51 of this embodiment includes an outer tube 51a, a distal wall portion 51b that closes the distal side A1 of the outer tube 51a, and a proximal wall portion 51c that closes the proximal side A2 of the outer tube 51a. A through hole that penetrates the distal wall portion 51b in the longitudinal direction A is formed in the distal wall portion 51b. Furthermore, a through hole that penetrates the proximal wall portion 51c in the longitudinal direction A is formed in the proximal wall portion 51c. The laser emitter 20 of this embodiment is movable in the longitudinal direction A relative to the inner tube 11 from a position where the flange portion 22b1 formed on the inner cylindrical portion 22b of the connector portion 22 abuts against the distal wall portion 51b in the longitudinal direction A to a position where the flange portion 22b1 abuts against the proximal wall portion 51c in the longitudinal direction A. By moving the laser emitter 20 within this range in the longitudinal direction A, the laser emitter 23 located in the first insertion passage 15 can be moved in the longitudinal direction A.

[0056] The expansion member 3 of this embodiment is supported on the outer surface of the elongated 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. That is, the inner portion 2a of the elongated 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 3a, distal joint portion 3b, and proximal joint portion 3c of the expansion member 3. In this embodiment, the distal protruding portion 11a of the inner tube 11 is provided with a laser transparent portion 2a1 at a position that is covered by the expansion portion 3a of the expansion member 3. In addition, the distal end portion 2b of the elongated member 2 in this embodiment is the portion of the distal protruding portion 11a of the inner tube 11 that is not covered by the expansion member 3.

[0057] In this embodiment, the distal protruding portion 11a of the inner tube 11 has a proximal side portion 11a1 and a distal side portion 11a2 with different outer diameters. The distal side portion 11a2 is continuous with the distal side A1 of the proximal side portion 11a1 and has a smaller diameter than the proximal side portion 11a1. The expansion portion 3a of the expansion member 3 in this embodiment covers the outside of the proximal side portion 11a1 in the radial direction C. The distal joint portion 3b of the expansion member 3 in this embodiment is joined to the outer surface of the distal side portion 11a2 by adhesive bonding, fusion, or the like. In this embodiment, the first insertion passage 15 and the third insertion passage 17 are defined inside the proximal side portion 11a1. In addition, the second insertion passage 16 in this embodiment is defined inside the distal side portion 11a2.

[0058] As shown in FIG. 5 , the intermediate section 11c of the inner tube 11 of this embodiment includes an intermediate main body section 11c1 that defines parallel first and second communication passages 18 and 19 therein, and a first branch section 11c2 and a second branch section 11c3 that branch off from the proximal side A2 of the intermediate main body section 11c1. The intermediate main body section 11c1 extends substantially parallel to the longitudinal direction A. The first branch section 11c2 is connected to the proximal side A2 of the intermediate main body section 11c1 and extends substantially parallel to the longitudinal direction A. The first branch section 11c2 defines the first communication passage 18 therein but does not define the second communication passage 19 therein. The proximal protrusion section 11b is connected to the proximal side A2 of the first branch section 11c2. The second branch section 11c3 is connected to the proximal side A2 of the intermediate main body section 11c1 and extends at an angle with respect to the longitudinal direction A. The second branch portion 11c3 opens to a side surface of the outer pipe body 12a of the outer pipe 12. The second branch portion 11c3 defines a second communication passage 19 therein, but does not define a first communication passage 18 therein.

[0059] As described above, the first lumen 4a, which includes the first insertion passage 15 and the first communication passage 18 and through which the laser emitter 20 can be inserted, is partitioned by the proximal side portion 11a1 of the distal protrusion 11a of the inner tube 11, the intermediate main body portion 11c1 and the first branch portion 11c2 of the intermediate portion 11c of the inner tube 11, and the proximal protrusion 11b of the inner tube 11.

[0060] In addition, the second lumen 4b, which includes the second insertion passage 16, the third insertion passage 17 and the second communication passage 19 and through which the guide wire GW can be inserted, is partitioned by the proximal side portion 11a1 and the distal side portion 11a2 of the distal protrusion portion 11a of the inner tube 11, and the intermediate main body portion 11c1 and the second branch portion 11c3 of the intermediate portion 11c of the inner tube 11.

[0061] Furthermore, the proximal side portion 11a1 of the distal protruding portion 11a of the inner tube 11 of this embodiment has a region made only of a light-transmitting material over a predetermined range in the longitudinal direction A. This region is the laser-transmitting portion 2a1 of the inner portion 2a of this embodiment.

[0062] In this embodiment, the third lumen 4c extends from a fluid supply / discharge port 12b1 formed in the main body 2c of the elongated member 2 to a 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 from the fluid supply / discharge device to the fluid storage space 5 through the third lumen 4c. When a fluid is supplied to the fluid storage space 5, the expansion member 3 can expand outward in the radial direction C. Meanwhile, the fluid contained in the fluid storage space 5 is discharged through the third lumen 4c 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.

[0063] The third lumen 4c of this embodiment is defined between the inner tube 11 and the outer tube 12. Specifically, the third lumen 4c of this embodiment is defined between the middle portion 11c of the inner tube 11 and the outer tube 12. The fluid supply / discharge port 12b1 is formed in the outer tube 12.

[0064] 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 third lumen 4c of this embodiment extends from the fluid supply / discharge port 12b1 of the outer tube hub 12b to the fluid containing space 5.

[0065] 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 sealing member 13 made of resin or the like closes the gap between the outer surface of the first branch portion 11c2 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 provision of the sealing member 13 makes it possible to prevent fluid such as a liquid flowing through the third lumen 4c from leaking from the proximal end opening 12b2.

[0066] 5 to 6B, the inner portion 2a of the elongated member 2 is provided with radiopaque markers 14a, 14b that indicate the positions of the distal end and proximal end of the laser transparent portion 2a1. The radiopaque markers 14a, 14b are radiopaque. Specifically, the radiopaque markers 14a, 14b may be formed of, for example, a material that is highly radiopaque. The radiopaque markers 14a, 14b may be formed of, for example, a material that is highly radiopaque, such as platinum, gold, iridium, or tungsten. The radiopaque markers 14a, 14b may be attached, for example, to the outer surface of the proximal portion 11a1 of the distal protruding portion 11a of the inner tube 11. The radiopaque markers 14a, 14b are not limited to being radiopaque and may be, for example, ultrasonically visible.

[0067] <Expansion member 3> As described above, the expansion member 3 is supported on the outer surface of the elongated 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.

[0068] The expansion member 3 in this embodiment is supported on the outer surface of the elongated member 2 in a state in which it surrounds the outside of the elongated member 2 in the radial direction C. In other words, the expansion member 3 surrounds the outside of the outer surface of the elongated member 2 in the radial direction C over the entire area in the circumferential direction B of the elongated member 2.

[0069] The expansion member 3 is configured to be expandable outward in the radial direction C of the elongated member 2. More specifically, the expansion member 3 of this embodiment is configured as an expandable membrane attached to the outer surface of the elongated member 2. Both ends of the expandable membrane serving as the expansion member 3 in the longitudinal direction A are annularly joined to the outer surface of the elongated member 2 by adhesive bonding, fusion, or the like, over the entire circumferential direction B of the elongated member 2. More specifically, the distal end of the expandable membrane serving as the expansion member 3 is annularly joined to the outer surface of the distal side portion 11a2 of the distal protrusion 11a of the inner tube 11 over the entire circumferential direction B. Furthermore, the proximal end of the expandable membrane 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 elongated member 2, and an annular fluid storage space 5 is defined between the central portion and the outer surface of the elongated member 2. When fluid is supplied to the fluid storage space 5 through the third lumen 4c of the elongated 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.

[0070] 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 elongated 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 the folds and protruding outward in the radial direction C of the elongated member 2. As a result, as shown in Figures 3 to 6B, 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.

[0071] 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.

[0072] In this embodiment, the expansion member 3 is configured as an expandable membrane attached to the outer surface of the elongated 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 elongated member 2. In other words, the fluid storage space 5 of the expansion member 3 may be a space defined only by the bag serving 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.

[0073] 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 expansion section 3a2 connected to the distal side A1 of the expansion main body section 3a1 and tapering in diameter toward the distal side A1 in the expanded state, and a proximal expansion section 3a3 connected to the proximal side A2 of the expansion main body section 3a1 and tapering in diameter toward the proximal side A2 in the expanded state. The distal joint section 3b is connected to the distal side A1 of the distal expansion section 3a2 of the expansion section 3a and is joined to the outer surface of the elongated member 2. Specifically, the distal joint section 3b of this embodiment is joined to the outer surface of the distal side section 11a2 of the distal protrusion 11a of the inner tube 11 of the elongated member 2. The proximal joint 3c is continuous with the proximal side A2 of the proximal expansion section 3a3 of the expansion section 3a, and is joined to the outer surface of the elongated member 2. Specifically, the proximal joint 3c in this embodiment is joined to the outer surface of the distal end of the outer tube main body 12a of the outer tube 12 of the elongated member 2.

[0074] The expansion member 3 of this embodiment includes a shock wave generating section 40a capable of generating shock waves as pressure waves caused by the laser emitted from the laser emitter 20. The shock wave generating section 40a will be described in detail below.

[0075] 5 to 6B, in the expansion member 3 of this embodiment, the expansion main body portion 3a1 is the shock wave generating portion 40a. The entire area of ​​the laser transmitting portion 2a1 in the longitudinal direction A is covered on the outside in the radial direction C by the expansion main body portion 3a1 as the shock wave generating portion 40a.

[0076] As shown in FIG. 6B , 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.

[0077] 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.

[0078] In the expansion main body portion 3a1 of the expansion member 3 of this embodiment, the first transmission layer 40a1, the second transmission layer 40a2, and the light absorption layer 40a3 are laminated in this order from the inside to the outside in the radial direction C. As a result, as shown in Fig. 11 , the laser emitted from the laser emission portion 23 of the laser emitter 20 housed in the first insertion passage 15 of the inner portion 2a of the elongated member 2 passes through the laser transmission portion 2a1, the fluid housed in the fluid housing 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 absorption layer 40a3 of the expansion main body portion 3a1 of the expansion member 3. In the light absorption layer 40a3, plasma is generated by the absorbed laser. The plasma generated in the light absorption layer 40a3 is more likely to remain within the light absorption layer 40a3 due to the first transmission layer 40a1 and second transmission layer 40a2 that cover the inside of the light absorption layer 40a3 in the radial direction C. This makes it possible to send laser-induced shock waves from the light absorption 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 is capable of emitting 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 a calcified region X in a blood vessel BV, the calcified region X can be fractured.

[0079] 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.

[0080] 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.

[0081] 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; polyamides; and various elastomers. 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.

[0082] 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.

[0083] 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.

[0084] It is preferable that at least one of the first transmission layer 40a1 and the second transmission layer 40a2 and the light absorption layer 40a3 extend over the entire area in the circumferential direction B of the elongated 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.

[0085] 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.

[0086] 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 the present 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, shock waves are generated in the direction changing section of the shock wave generating section 40a 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.

[0087] 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.

[0088] Second Embodiment Next, a catheter 101 as a second embodiment of a catheter according to the present disclosure will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view of the catheter 101 taken along the longitudinal direction A. The catheter 101 of this embodiment is different from the catheter 1 of the first embodiment described above (see Figs. 1 to 6B) in the configuration of the inner tube 111 of the elongated member 2, but has the other configurations in common. Here, only the above-mentioned differences will be described, and a description of the common configuration will be omitted.

[0089] As shown in Figure 7, the inner tube 111 of the elongated member 2 of this embodiment has a distal protrusion 11a that protrudes toward the distal side A1 from the outer tube 12, a proximal protrusion 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 protrusion 11a and the proximal protrusion 111b.

[0090] The intermediate portion 111c of this embodiment defines the parallel first and second communication passages 18 and 19. The intermediate portion 111c of this embodiment does not include a branch portion. Therefore, the intermediate portion 111c of this embodiment protrudes from the proximal end opening 12b2 of the outer tube 12 to the proximal side A2.

[0091] In contrast, the proximal protrusion 111b of this embodiment includes a first branch portion 111b1 and a second branch portion 111b2 branching from the intermediate portion 111c. The first branch portion 111b1 defines the first communication passage 18 therein, but does not define the second communication passage 19 therein. The first branch portion 111b1 of this embodiment includes a holder 51 that holds the laser emitter 20 inserted into the first lumen 4a so that it can move relatively in the longitudinal direction A. The holder 51 has the same configuration as that shown in the first embodiment described above. The second branch portion 111b2 defines the second communication passage 19 therein, but does not define the first communication passage 18 therein.

[0092] Thus, the second lumen 4b defined inside the inner tube 111 is not limited to a 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 catheter 1 having the so-called rapid exchange type second lumen 4b shown in FIGS. 1 to 6B , but may have a configuration having the so-called over-the-wire type second lumen 4b, as in the catheter 101 of this embodiment.

[0093] [Third Embodiment] Next, a catheter 201 as a third embodiment of a catheter according to the present disclosure will be described with reference to Figures 8 and 9. Figure 8 is a cross-sectional view of the catheter 201 taken along the longitudinal direction A. Figure 9 is a diagram showing the details of the laser emission unit 223 of the laser emitter 20. The catheter 201 of this embodiment is different from the catheter 1 of the first embodiment described above (see Figures 1 to 6B) in the configuration of the inner tube 211 of the elongated member 2 and the configuration of the laser emission unit 223 of the laser emitter 20, but the other configurations are the same. Here, only the above-mentioned differences will be described, and a description of the common configuration will be omitted.

[0094] 8 , in the catheter 201 of this embodiment, the first insertion passage 15 and the second insertion passage 16 communicate with each other in the longitudinal direction A. The main body 2c of the elongated member 2 of this embodiment defines a common passage 250 communicating with the proximal side A2 of the first insertion passage 15 in the longitudinal direction A, and a first branch passage 251 and a second branch passage 252 branching from a junction 250a at the proximal end of the common passage 250 in the longitudinal direction A. In other words, in the catheter 201 of this embodiment, the first communication passage 15 is part of the first lumen 4a and also part of the second lumen 4b.

[0095] More specifically, the inner tube 211 of the elongated member 2 in this embodiment has a distal protrusion 211a that protrudes toward the distal side A1 from the outer tube 12, a proximal protrusion 211b that protrudes toward the proximal side A2 from the outer tube 12, and an intermediate portion 211c that is covered on the outside in the radial direction C by the outer tube 12 and connects the distal protrusion 211a and the proximal protrusion 211b.

[0096] The distal protruding portion 211a defines therein a first insertion passage 15 and a second insertion passage 16 that communicate with each other in the longitudinal direction A. More specifically, the distal protruding portion 211a in this embodiment is a tubular portion that extends in the longitudinal direction A so as to include the central axis O of the expansion member 3 in the expanded state, and defines therein a single lumen that opens to the outside at the distal end.

[0097] The intermediate portion 211c of this embodiment includes a common portion 211c1 that defines the common path 250, a first branch portion 211c2 that defines the first branch path 251, and a second branch portion 211c3 that defines the second branch path 252. The common portion 211c1 is a tubular portion that continues to the proximal side A2 of the distal protrusion 211a. The common portion 211c1 defines a single lumen that serves as the common path 250 and extends in the longitudinal direction A so as to include the central axis O of the expansion member 3 in the expanded state. The first branch portion 211c2 is continuous to the proximal side A2 of the common portion 211c1 and extends in the longitudinal direction A. The first branch path 251 defined by the first branch portion 211c2 is a part of the first lumen 4a through which the laser emitter 20 can be inserted. The second branch portion 211c3 is continuous with the proximal side A2 of the common portion 211c1 and extends at an angle with respect to the longitudinal direction A. The second branch portion 211c3 opens to a side surface of the outer tube 12. A second branch passage 252 defined by the second branch portion 211c3 is a part of the second lumen 4b through which a guidewire GW (see FIG. 1, etc.) can be inserted.

[0098] The proximal protrusion 211b is connected to the proximal side A2 of the first branch 211c2. The proximal protrusion 211b of this embodiment includes a holding portion 51 that holds the laser emitter 20 inserted into the first lumen 4a so that the laser emitter 20 can move relatively in the longitudinal direction A. The holding portion 51 has the same configuration as that shown in the first embodiment described above.

[0099] As described above, the first insertion passage 15 in this embodiment is part of the first lumen 4a through which the laser emitter 20 is inserted, and is also part of the second lumen 4b through which the guidewire GW is inserted. Therefore, body fluids such as blood may enter the first insertion passage 15 from the opening at the distal end of the distal protrusion 211a through the second insertion passage 16. In such a case, the laser emitted from the laser emission unit 223 of the laser emitter 20 located in the first insertion passage 15 may be refracted at the interface between the laser emission unit 223 and the body fluid in the first insertion passage 15, potentially weakening the intensity of the laser that reaches the expansion member 3 through the laser transparent portion 2a1. Therefore, the proximal protrusion 211b in this embodiment is provided with a flush port 211b1 into which a liquid such as saline can be injected in order to flush body fluids such as blood from the first insertion passage 15 through the opening at the distal end of the distal protrusion 211a. The flush port 211 b 1 communicates with the first insertion passage 15 and the second insertion passage 16 through the first branch passage 251 and the common passage 250 .

[0100] In this way, the first lumen 4a through which the laser emitter 20 can be inserted and the second lumen 4b through which the guide wire GW can be inserted may be configured to merge at the junction 250a, and the same lumen may be shared on the distal side A1 from this junction 250a.

[0101] The catheter 201 of this embodiment is movable to a target site along the guidewire GW inserted through the second lumen 4b. At this time, the distal end of the laser emitter 20 is located in the first branch passage 251. Thereafter, the guidewire GW is retracted to the proximal side A2 from the junction 250a. That is, the distal end of the guidewire GW is retracted to the second branch passage 252. Next, the laser emitter 20 is moved to the distal side A1 from the junction 250a, and the laser emitter 223 of the laser emitter 20 is disposed in the first insertion passage 15. Therefore, with the catheter 201 of this embodiment, it is preferable that the position of the junction 250a located inside the living body can be identified. It is also preferable that the position of the laser emitter 223 located at the distal end of the laser emitter 20 can be identified. That is, it is preferable that the elongated member 2 is provided with a contrast marker 14c having X-ray contrast properties at the position of the junction 250a in the longitudinal direction A. 9 , the laser emitter 20 preferably includes a contrast marker 226 having X-ray contrast near the position of the laser emitter 223. This allows the operator of the catheter 201, such as a surgeon, to confirm the position of the confluence 250a using the contrast marker 14c during surgery, and also allows the operator to confirm the position of the contrast portion provided at the distal end of the guidewire GW using the contrast marker 14c. Furthermore, the elongated member 2 preferably includes a contrast marker 14d at the position of the first branch 211c2 so that the distal end of the laser emitter 223 can be positioned near the proximal side of the confluence 250a. This allows the operator to confirm the position of the laser emitter 223 of the laser emitter 20 using the contrast marker 14d and the contrast marker 226 during surgery. This facilitates the operator's manipulation of the laser emitter 20 and the guidewire GW.

[0102] The contrast markers 14c, 14d and the contrast marker 226 are not limited to having X-ray contrast properties, but may have ultrasound visibility, for example.

[0103] 9 , the laser emission unit 223 of this embodiment includes a protective cover 227 that covers the laser fiber 31 and is laser-transmissive. More specifically, the protective cover 227 of this embodiment covers the laser emission surface 31 a of the laser fiber 31 with an air layer interposed between the protective cover 227 and the laser emission surface 31 a of the laser fiber 31. By providing such a protective cover 227, the laser emitted from the laser emission surface 31 a can be more effectively prevented from being refracted in an unintended direction than in a state where the laser emission surface 31 a is in contact with a bodily fluid such as blood, and the laser emitted from the laser emission surface 31 a can be emitted in a desired direction (radial direction C in this embodiment).

[0104] [Fourth embodiment] Next, a catheter 301 as a fourth embodiment of a catheter according to the present disclosure will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view of the catheter 301 taken along the longitudinal direction A. The catheter 301 of this embodiment is different from the catheter 201 of the third embodiment described above (see Figs. 8 and 9) in the configuration of the second branch portion 311c3 of the inner tube 311, but has the other configurations in common. Here, only the above-mentioned differences will be described, and a description of the common configuration will be omitted.

[0105] 10 , the second branch portion 311c3 of this embodiment does not open to the side surface of the outer tube 12, but protrudes from the proximal end opening 12b2 of the outer tube 12 to the proximal side A2. As such, the second lumen 4b defined inside the inner tube 311 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 catheter 201 having a so-called rapid exchange type second lumen 4b shown in FIG. 8 , but may also have a configuration having a so-called over-the-wire type second lumen 4b, as in the catheter 301 of this embodiment.

[0106] As shown in FIG. 12, by using a catheter according to the present disclosure, such as those exemplified in the first to fourth embodiments, a treatment method including the following steps (I) to (III) can be carried out.

[0107] (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.

[0108] 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.

[0109] 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.

[0110] In the first embodiment described above, the expansion member 3 includes the shock wave generating unit 40a (see FIGS. 5 to 6B ), but this configuration is not limited thereto. As shown in FIG. 13 , the elongated member 2 may include the shock wave generating unit 40a. In FIG. 13 , the inner portion 2a of the elongated member 2 includes the shock wave generating unit 40a. Specifically, the shock wave generating unit 40a shown in FIG. 13 includes a transmission layer 41 that allows the laser emitted from the laser emitter 20 to transmit in the radial direction C, and a light absorption layer 42 disposed outside the transmission layer 41 in the radial direction C. More specifically, the shock wave generating unit 40a shown in FIG. 13 includes the transmission layer 41 and the light absorption layer 42. The transmission layer 41 may have the same configuration as the laser transmission portion 2a1 described above. The light absorption layer 42 may have the same configuration as the light absorption layer 40a3 described above. By doing so, the laser emitted from the laser emitter 20 housed in the first insertion passage 15 of the inner portion 2a of the elongated member 2 passes through the transmission layer 41 and is absorbed by the light absorption layer 42. In the light absorption layer 42, plasma is generated by the absorbed laser. The plasma generated in the light absorption layer 42 is more likely to remain within the light absorption layer 42 due to the transmission layer 41 covering the inner side of the light absorption layer 42 in the radial direction C. This allows laser-induced shock waves to be sent from the light absorption layer 42 toward the outside in the radial direction C. This laser-induced shock wave is transmitted by the fluid contained in the fluid storage space 5 and the expansion member 3 and is emitted toward the outside of the expansion member 3 in the radial direction C. Here, as a modification of the first embodiment described above, a configuration in which the inner portion 2a of the elongated member 2 includes a shock wave generating unit 40a has been exemplified. However, a similar configuration may be applied to the second to fourth embodiments.

[0111] The present disclosure relates to catheters.

[0112] 1, 101, 201, 301: catheter 2: elongated 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 expansion portion 3a3: proximal expansion portion 3b: distal joint portion 3c: proximal joint portion 4a: first lumen 4b: second lumen 4c: third lumen 5: fluid storage space 11, 111, 211, 311: inner tube 11a, 211a: distal protrusion portion 11a1: proximal side portion 11a2: distal side portion 11b, 111b, 211b: proximal protrusion portion 11c, 111c, 211c: intermediate portion 11c1: intermediate main body portion 11c2: First branch portion 11c3: Second branch portion 12: Outer tube 12a: Outer tube main body 12b: Outer tube hub 12b1: Fluid supply / discharge port portion 12b2: Proximal end port portion 13: Sealing member 14a, 14b, 14c, 14d: Contrast marker 15: First insertion passage 15a: Closing wall 16: Second insertion passage 17: Third insertion passage 18: First communication passage 19: Second communication passage 20: Laser emitting body 21: Laser emitting body 22: Connector portion 22a: Connector body 22b: Inner cylinder portion 22b1: Flange portion 23, 223: Laser emitting portion 24: Drive transmission connector 25: Laser non-emitting portion 25a: Coating portion 31: Laser fiber 31a: Laser emitting surface 32: Fiber coating layer 40a: Shock wave generating section 40a1: First transmission layer 40a2: Second transmission layer 40a3: Light absorbing layer 41: Transmission layer 42: Light absorbing layer 51: Holding section 51a: Outer tube section 51b: Distal wall section 51c: Proximal wall section 111b1: First branch section 111b2: Second branch section 211b1: Flush port 211c1: Common section 211c2: First branch section 211c3, 311c3: Second branch section 226: Contrast marker 227: Protective cover 250: Common channel 250a: Junction section 251: First branch section 252: Second branch section A: Longitudinal direction A1: Distal side A2: Proximal side B: Circumferential direction C: Radial direction BV: Blood vessel GW: Guidewire L1: Irradiation range L2: Radial distance from the laser emitter located in the first insertion passage to the expansion member O: Central axis of the expansion member X: Calcified area

Claims

1. A laser emitter capable of emitting a laser, an elongated member into which the laser emitter can be inserted, and an expansion member covering the radial outside of the elongated member and capable of expanding and contracting in the radial direction, wherein the elongated member comprises: an inner portion that is covered by the expansion member on the radial inside of the expansion member and includes a laser transparent portion that can transmit the laser emitted from the laser emitter in the radial direction; and a distal end portion that is connected to the inner portion on the distal side of the longitudinal direction of the elongated member relative to the expansion member, wherein the expansion member is capable of emitting the laser emitted from the laser emitter or a pressure wave caused by the laser outward in the radial direction, and the inner portion of the elongated member extends in the longitudinal direction so as to include the central axis of the expansion member in an expanded state, and defines a first insertion passage through which the laser emitter can be inserted, The distal end of the elongate member extends in the longitudinal direction so as to include the central axis, and defines a second insertion passage through which a guide wire can be inserted.

2. A catheter according to claim 1, wherein the expansion member is provided with a shock wave generating section capable of generating shock waves as the pressure waves by the laser emitted from the laser emitter.

3. A catheter as described in claim 1, wherein the elongated member is provided with a shock wave generating section capable of generating shock waves as the pressure waves by the laser emitted from the laser emitter.

4. A catheter according to any one of claims 1 to 3, wherein the elongated member has a main body portion connected to the inner portion proximal to the expansion member in the longitudinal direction, the first insertion passage and the second insertion passage are not connected in the longitudinal direction, the inner portion of the elongated member defines a third insertion passage arranged in parallel to the first insertion passage and connected to the second insertion passage, and the main body portion of the elongated member defines a first communication passage connected to the proximal side of the first insertion passage in the longitudinal direction, and a second communication passage connected to the proximal side of the third insertion passage in the longitudinal direction.

5. A catheter as described in any one of claims 1 to 3, wherein the elongated member has a main body portion connected to the inner portion on the proximal side in the longitudinal direction relative to the expansion member, the first insertion passage and the second insertion passage are connected in the longitudinal direction, and the main body portion of the elongated member defines a common passage connected to the proximal side in the longitudinal direction of the first insertion passage, and a first branch passage and a second branch passage branching from a junction at the proximal end of the common passage in the longitudinal direction.

6. The catheter according to claim 5, wherein the main body of the elongated member is provided with a marker that is radiopaque or ultrasonically visible at the position of the confluence in the longitudinal direction.

7. A catheter according to any one of claims 1 to 3, wherein the laser emitter comprises: a laser emitting section in which the laser fiber capable of emitting the laser is not covered with a fiber coating layer; and a laser non-emitting section in which the laser fiber is covered with the fiber coating layer.

8. The catheter according to claim 7, wherein the non-laser emitting portion comprises a coated portion whose outer surface is formed with a hydrophilic coating.

9. A catheter according to claim 5, wherein the laser emitter comprises: a laser emitting section in which a laser fiber capable of emitting the laser is not covered with a fiber coating layer; and a laser non-emitting section in which the laser fiber is covered with the fiber coating layer; and the laser emitting section comprises a protective cover that covers the laser fiber and is transparent to the laser.

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