JP2017063830A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter which can be moved smoothly in a living body lumen, and in which push-in properties of an expansion part into a narrow part have been improved.SOLUTION: A balloon catheter includes: a long-sized flexible shaft 110 provided with an outer tube 111 having a lumen and an inner tube 112 disposed in the lumen of the outer tube; an expansion part 120 which can expand and contract accompanying inflow and outflow of fluid F, the tip of which is fixed to the tip of the inner tube, and the base end part of which is fixed to the tip of the outer tube; an expansion lumen 115 formed between the outer peripheral surface of the inner tube and the inner peripheral part of the outer tube, in which the fluid can circulate; and a fluid adjustment part 130 for controlling the movement of the fluid in the expansion lumen. The fluid adjustment part transits from a first state in which a part between the expansion lumen and the expansion part is closed to a second state in which the expansion lumen is communicated with the expansion part when the fluid is injected in the expansion lumen and the internal pressure of the expansion lumen exceeds a predetermined value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a balloon catheter.

  A balloon catheter is widely known as a medical device for expanding a stenosis formed in a living body.

  In general, a balloon catheter has a long shaft and an expansion portion that is provided on the distal end side of the shaft and can expand and contract by inflowing and discharging fluid. Generally, the shaft is formed of a flexible material so that it can move following the shape of a living body lumen such as a meandering or curved blood vessel (see Patent Document 1 below).

JP 2002-291897

  However, for example, when the expansion portion is pushed into a stenosis portion or the like that has become hard due to progress of calcification or the like, if the shaft is too flexible, it is difficult for the surgeon to push the balloon catheter into the expansion portion, and the expansion portion is placed in the stenosis portion. It may be difficult to push in the placement.

  The present invention has been made to solve the above-described problems, and provides a balloon catheter that enables smooth movement in a living body lumen and further improves pushability of an expansion portion into a stenosis portion. With the goal.

  A balloon catheter according to the present invention includes a flexible long shaft including an outer tube having a lumen and an inner tube disposed in the lumen of the outer tube, and a distal end portion of the inner tube. An extended portion fixed to the distal end portion and having a base end portion fixed to the distal end portion of the outer tube, and can be expanded and contracted as fluid flows in and out, an outer peripheral surface of the inner tube, and the outer tube And an expansion lumen through which the fluid can flow, and a fluid adjustment section that controls movement of the fluid in the expansion lumen. The fluid adjustment unit includes a first state in which the space between the expansion lumen and the expansion portion is closed, and a second state in which the expansion lumen and the expansion portion are communicated with each other. In the first state, the fluid adjustment unit maintains a state in which the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube are in contact with each other directly or through a gap member. When the fluid is injected and the internal pressure of the expansion lumen exceeds a predetermined value, the first state is shifted to the second state.

  According to the balloon catheter of the present invention, in a state where fluid is not injected into the expansion lumen, the inside of the shaft is not pressurized, and the shaft can be kept in a relatively flexible state. In this state, the balloon catheter can move smoothly through the living body lumen. On the other hand, by injecting the fluid into the expansion lumen so that the internal pressure of the expansion lumen is a predetermined value or less, the inside of the shaft can be pressurized and the rigidity of the shaft can be increased while maintaining the contraction state of the expansion portion. For this reason, the force with which the surgeon pushes the shaft is transmitted well to the expanded portion, and the pushability of the expanded portion into the narrowed portion is improved.

It is a figure which shows each part of the balloon catheter which concerns on 1st Embodiment, Comprising: (A) is a figure which simplifies and shows the whole structure, (B) is a figure which expands and shows the expansion part of the contracted state. . It is sectional drawing which follows the 2A-2A line | wire of FIG. 1 (B), (A) is a figure which shows a mode that the fluid is not inject | poured into an expansion lumen, (B) is between an expansion lumen and an expansion part. The figure which shows a mode that the fluid is inject | poured into the expansion lumen | rumen in the state which was closed, (C) is a figure which shows a mode that the expansion lumen and the expansion part are connected. It is a figure which shows the usage example of the balloon catheter which concerns on 1st Embodiment, Comprising: (A) is a figure which shows a mode that the balloon catheter is moving in the meandering blood vessel, (B) is an expansion part in a stenosis part. The figure which shows a mode that is pushed in, (C) is a figure which shows a mode that the expansion part was expanded in the constriction part. It is the schematic which shows the balloon catheter which concerns on the modification of 1st Embodiment, Comprising: (A) is a top view which simplifies and shows the front end side, (B) is the 4B-4B line | wire of FIG. 4 (A). FIG. 4C is a cross-sectional view taken along the line, and shows a state in which fluid is injected into the expansion lumen in a state where the space between the expansion lumen and the expansion portion is closed, and FIG. 4C is a view of 4B-4B in FIG. It is sectional drawing which follows a line | wire, Comprising: It is a figure which shows a mode that the expansion lumen and the expansion part were connected. It is sectional drawing which shows the balloon catheter which concerns on 2nd Embodiment, Comprising: (A) is a figure which shows a mode that the fluid is inject | poured into the expansion lumen since the space between the expansion lumen and the expansion portion is closed. B) is a diagram illustrating a state in which the extension lumen and the extension portion are communicated with each other. It is sectional drawing which shows the balloon catheter which concerns on the modification of 2nd Embodiment, Comprising: (A) shows a mode that the fluid is inject | poured into the expansion lumen in the state with which the space between the expansion lumen and the expansion part was closed. The figure shown, (B) is a figure which shows the state which communicated between the expansion lumen and the expansion part.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the following description does not limit the technical scope and terms used in the claims. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from actual ratios.

(First embodiment)
A balloon catheter 100 according to the present embodiment will be described with reference to FIGS. 1 and 2 are views showing each part of the balloon catheter 100 according to the present embodiment. FIG. 3 is a schematic view showing an example of use of the balloon catheter 100 according to the present embodiment. 1 (A) and 1 (B) and FIGS. 3 (A) and 3 (B) are diagrams simply showing the shape of the expanded portion 120 in a contracted state. As shown in A), the extended portion 120 is folded with respect to the outer periphery of the inner tube 112 of the shaft 110.

  The balloon catheter 100 according to the present embodiment is configured as a medical device that spreads and treats a stenosis portion generated in a blood vessel, a bile duct, a trachea, an esophagus, a urethra, or other living body lumen.

  As shown in FIGS. 1A and 2A, the balloon catheter 100 is provided with a long shaft 110 having flexibility and a distal end side of the shaft 110. The expansion part 120 which can be expanded and contracted, the fluid adjustment part 130 which controls the movement of the fluid F in the expansion lumen 115 in the shaft 110, and the hub 140 fixed to the proximal end of the shaft 110 are included. In the present specification, the side to be inserted into the living body is referred to as “tip” or “tip side”, and the proximal side is referred to as “base end” or “base end side”.

  As shown in FIGS. 1B and 2A, the shaft 110 includes an outer tube 111 that is a tubular body having an open front end and a base end, and an inner tube 112 disposed in the lumen of the outer tube 111. It is equipped with.

As shown in FIG. 2 (A), an expansion lumen 115 through which an expansion fluid F for expanding the expansion portion 120 circulates between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111. Is formed. A guide wire lumen through which the guide wire W is inserted is formed inside the inner tube 112 as shown in FIG. The fluid F may be a gas or a liquid, and examples thereof include gases such as helium gas, CO ₂ gas, and O ₂ gas, and liquids such as physiological saline and contrast medium.

  As shown in FIG. 1A, the balloon catheter 100 according to the present embodiment has an inner tube 112 via a guide wire opening 113 formed in the middle between the distal end side and the proximal end side of the shaft 110. It is configured as a so-called rapid exchange type catheter into which a guide wire W is introduced. However, the balloon catheter 100 may be configured as a so-called over-the-wire catheter.

  As shown in FIG. 2A, the distal end portion of the inner tube 112 penetrates through the inside of the extended portion 120 and opens at the distal end side with respect to the expanded portion 120. The inner tube 112 includes a portion that becomes a boundary between the cylindrical portion 121 and the distal end side tapered portion 122a of the expansion portion 120, and a portion that becomes a boundary between the cylindrical portion 121 and the proximal end side tapered portion 122b of the expansion portion 120. In addition, contrast markers 114a and 114b are provided.

  The outer tube 111 and the inner tube 112 can be heat-sealed and are formed of a material having a certain degree of flexibility. As such a material, for example, a thermoplastic resin is preferably used. More specifically, polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, polyvinyl chloride resin, polyamide, polyamide elastomer , Polyester, polyester elastomer, thermoplastic polyurethane and the like.

  The expansion part 120 expands a stenosis part etc. by expanding. The proximal end portion of the expansion portion 120 is fixed to the distal end portion of the outer tube 111, and the distal end portion of the expansion portion 120 is fixed to the distal end portion of the inner tube 112. In the contracted state, the expansion part 120 is folded around the outer periphery of the inner tube 112 as shown in FIG.

  The extension 120 is preferably formed of a material having a certain degree of flexibility. For example, polyethylene, polypropylene, polybutene, an ethylene-propylene copolymer, an ethylene-vinyl acetate copolymer, an ionomer, or two of these. Polyolefins such as mixtures of more than one species, soft polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, fluororesins and other thermoplastic resins, silicone rubbers, latex rubbers and the like can be used.

  The fluid adjustment unit 130 communicates between the expansion lumen 115 and the expansion unit 120 in a first state in which the space between the expansion lumen 115 and the expansion unit 120 is closed (see FIGS. 2A and 2B). 2 states (see FIG. 2C). When the fluid F is injected into the expansion lumen 115 and the internal pressure of the expansion lumen 115 exceeds a predetermined value, the fluid adjustment unit 130 shifts from the first state to the second state.

  As shown in FIGS. 2A and 2B, the fluid adjusting unit 130 includes a fused portion 131 in which the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are fused in the first state. Prepare. The fusion part 131 can be formed by a method such as heat fusion, high-frequency fusion, or ultrasonic fusion. In the first state, the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are in direct contact with each other through the fused portion 131. For this reason, it is not necessary to provide a separate member for forming the first state, and the fusion portion 131 can be easily formed on the balloon catheter 100. Moreover, the manufacturing cost of the balloon catheter 100 can be suppressed.

  The position at which the fused portion 131 is formed is not particularly limited as long as it is between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111. However, as shown in FIG. It is preferable to be formed near the boundary with the portion 120 (the tip of the outer tube 111). Thus, when the fluid F is injected into the expansion lumen 115 so that the internal pressure of the expansion lumen 115 becomes a predetermined value or less, the expansion portion 120 is maintained in a contracted state, and the shaft 110 reaches the tip portion of the shaft 110. The rigidity can be increased. For this reason, the force which pushes in the surgeon's shaft 110 becomes easy to be transmitted by the expansion part 120. FIG.

  When the fluid F is injected into the expansion lumen 115 and the internal pressure of the expansion lumen 115 exceeds a predetermined value, the fused portion 131 is broken as shown in FIG. Is in communication.

  For this reason, when the fluid F is not injected into the expansion lumen 115, the shaft 110 is not pressurized as shown in FIG. When the fluid F is injected into the expansion lumen 115 so that the internal pressure of the expansion lumen 115 is a predetermined value or less, the shaft 110 is maintained while the expansion portion 120 is contracted as shown in FIG. Since the inside is pressurized, the rigidity of the shaft 110 becomes relatively high. When the internal pressure of the expansion lumen 115 exceeds a predetermined value, as shown in FIG. 2C, the fusion portion 131 is broken and the expansion lumen 115 and the expansion portion 120 communicate with each other. Can be expanded.

  In addition, the predetermined value of the internal pressure of the expansion lumen 115 when the fusion part 131 breaks is, for example, the outer surface of the inner tube 112 in the fusion part 131 so that it is equal to or less than the prescribed recommended pressure (NP) of the expansion part 120. It is preferable to set a fixing force between the outer surface of the outer tube 111 and the inner surface of the outer tube 111. Thereby, when shifting from the first state to the second state, it is possible to prevent the expansion portion 120 from being damaged due to a pressure greater than the recommended recommended pressure being applied to the expansion portion 120.

  Note that when the fusion part 131 is shifted from the first state to the second state, the fusion part 131 is broken, and the expansion lumen 115 and the expansion part 120 communicate with each other. Therefore, the fusion | melting part 131 does not return to a 1st state automatically, after transfering to a 2nd state. That is, the transition of the fused part 131 from the first state to the second state is irreversible. For this reason, the surgeon can discharge the fluid F in the expansion part 120 after the expansion part 120 is expanded, and can easily contract the expansion part 120.

  As shown in FIG. 1A, the hub 140 includes a proximal end opening 141 that functions as a port through which the expansion fluid F flows in and out. The proximal end opening 141 communicates with an expansion lumen 115 formed between the outer tube 111 and the inner tube 112.

  Examples of the constituent material of the hub 140 include thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.

  Next, referring to FIG. 3, after passing the shaft 110 and the expanded portion 120 into the meandering blood vessel V1, the expanded portion 120 is pushed into the narrowed portion N where calcification has progressed in the blood vessel V2, and the narrowed portion N is pushed. An example procedure for spreading will be described.

  First, prior to the introduction of the balloon catheter 100, the balloon catheter 100 in a state where the fluid F has not been injected into the dilation lumen 115 is put together with the guide wire W arranged in the blood vessel V2, and the dilation portion 120 is made to be the stenosis portion N. Deliver to nearby. Since the inside of the shaft 110 is in an unpressurized state, the shaft 110 maintains a relatively flexible state. For this reason, even if there is a meandering blood vessel V1 as shown in FIG. 3A before the expansion portion 120 is delivered around the stenosis N, the shaft 110 follows the meandering blood vessel V1. Therefore, the balloon catheter 100 can be moved smoothly.

  Next, after injecting the fluid F into the expansion lumen 115 so that the internal pressure of the expansion lumen 115 becomes a predetermined value or less, the expansion portion 120 is pushed into the narrowed portion N. Since the inside of the shaft 110 is pressurized and the rigidity of the shaft 110 is increased, the force with which the surgeon pushes the hub 140 is well transmitted to the expanded portion 120 through the shaft 110, and the calcification progresses and becomes hard. The expanded portion 120 can be easily pushed into the narrowed portion N. As described above, in this embodiment, the fusion portion 131 is formed in the vicinity of the boundary between the expansion lumen 115 and the expansion portion 120 (the front end portion of the outer tube 111). Since the rigidity is increased by being pressurized, the expanded portion 120 can be pushed into the narrowed portion N more easily.

  Next, it is confirmed that the expanded portion 120 is disposed in the constricted portion N, and the fluid F is further injected into the expanded lumen 115 so that the internal pressure of the expanded lumen 115 exceeds a predetermined value. Thereby, since the expansion lumen 115 and the expansion portion 120 communicate with each other, the expansion portion 120 expands and the constriction portion N is pushed open.

  Next, the balloon catheter 100 is removed from the blood vessel V2.

  As described above, according to the balloon catheter 100 according to the present embodiment, the flexible shaft 110 including the outer tube 111 having the inner lumen and the inner tube 112 disposed in the inner lumen of the outer tube 111, and the distal end portion are the inner portions. An expansion portion 120 that is fixed to the distal end portion of the tube 112 and has a proximal end portion fixed to the distal end portion of the outer tube 111 and can be expanded and contracted by inflow and discharge of the fluid F; and an outer peripheral surface of the inner tube 112 An expansion lumen 115 that is formed between the outer peripheral surface of the outer tube 111 and allows the fluid F to flow therethrough, and a fluid adjustment unit 130 that controls the movement of the fluid F in the expansion lumen 115. The fluid adjustment unit 130 includes a first state in which the space between the expansion lumen 115 and the expansion portion 120 is closed, and a second state in which the space between the expansion lumen 115 and the expansion portion 120 is communicated. In the first state, the fluid adjusting unit 130 maintains a state in which the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are in direct contact with each other, and injects the fluid F into the expansion lumen 115 to increase the internal pressure of the expansion lumen 115. Shifts from the first state to the second state when exceeds a predetermined value.

  For this reason, in the state where the fluid F is not injected into the expansion lumen 115, the inside of the shaft 110 is not pressurized, and the shaft 110 can maintain a relatively flexible state. In this state, the balloon catheter 100 can move smoothly through the living body lumen. On the other hand, by injecting the fluid F into the expansion lumen 115 so that the internal pressure of the expansion lumen 115 becomes a predetermined value or less, the inside of the shaft 110 is pressurized and the rigidity of the shaft 110 is increased while maintaining the contraction state of the expansion portion 120. Can be increased. For this reason, the force by which the surgeon pushes the shaft 110 is transmitted well to the expanded portion 120, and the pushability of the expanded portion 120 to the narrowed portion can be improved.

  In addition, the fluid adjustment unit 130 includes a fusion part 131 in which the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are fused in the first state, and the outer peripheral surface of the inner tube 112 and the outer tube 111. In the first state, the inner peripheral surface directly contacts with the fused portion 131. Therefore, it is not necessary to provide a separate member so that the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are in contact with each other, and the fusion portion 131 can be easily formed on the balloon catheter 100. Moreover, the manufacturing cost of the balloon catheter 100 can be suppressed.

  The balloon catheter 100 is not limited to the single-layer outer tube 111 and the single-layer inner tube 112. For example, the outer tube 111 and the inner tube 112 may have a two-layer structure having an inner layer and an outer layer disposed radially outward of the inner layer. In such a case, the outer tube 111 preferably has a first inner layer and a first outer layer made of a material having a higher melting point than the material constituting the first inner layer. The inner tube 112 preferably has a second inner layer and a second outer layer made of a material having a melting point lower than that of the material constituting the second inner layer. Thus, when the inner peripheral surface of the outer tube 111 and the outer peripheral surface of the inner tube 112 are fused to form the fused portion 131, the inner layer of the outer tube 111 having a low melting point and the outer layer of the inner tube 112 having a low melting point are formed. By fusing, the fused part 131 can be formed. For this reason, when expanding the expansion part 120 by breaking the fusion part 131, the influence of the fracture of the fusion part 131 on the outer tube 111 and the inner tube 112 can be suppressed.

(Modification of the first embodiment)
FIG. 4 is a view showing a balloon catheter 100 according to a modification of the first embodiment. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 4 (A), the balloon catheter 100 according to the modification of the first embodiment is an annular shape in which the fluid adjusting unit 230 applies a tightening force along the outer peripheral surface of the outer tube 111 in the first state. A member 231 is provided, and the annular member 231 is different from the first embodiment in that the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are in direct contact with each other in the first state. Hereinafter, the balloon catheter 100 according to a modification of the first embodiment will be described in detail.

  The constituent materials of the inner tube 112 and the outer tube 111 are not limited to materials that can be heat-sealed. The inner tube 112 and the outer tube 111 are made of a material having a certain degree of flexibility. Examples of such materials include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, polyvinyl chloride resin, polyamide. Polyamide elastomer, polyester, polyester elastomer, polyurethane, fluororesin, silicone rubber, latex rubber and the like can be used.

  As shown in FIGS. 4A and 4B, the annular member 231 makes at least one round of the outer periphery in a range where it overlaps with the distal end portion of the outer tube 111 at the base end portion of the expansion portion 120 in the first state. It is comprised by the band-shaped member bound. A knot 232 connecting both ends is formed on the annular member 231.

  In the first state, the diameter of the portion of the outer tube 111 that is bound to the annular member 231 is reduced, and the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are directly connected as shown in FIG. Touch. As described above, since the annular member 231 is disposed at a portion overlapping the distal end portion of the outer tube 111 at the proximal end portion of the expansion portion 120, the annular member 231 can be pressurized to the distal end side in the shaft 110 to increase rigidity. Thus, the expanded portion 120 can be pushed into the narrowed portion N more easily. The position where the annular member 231 is provided is not particularly limited as long as a tightening force can be applied along the outer periphery of the outer tube 111. You may provide in the part which is not.

  Since the annular member 231 is provided on the outer peripheral side of the outer tube 111, a member is provided between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111, or the outer peripheral surface of the inner tube 112 and the outer tube 111. The balloon catheter 100 can be manufactured relatively easily as compared with the case where the inner peripheral surface of the balloon catheter is fused.

  As shown in FIG. 4C, the knot 232 is configured to be unwound when the fluid F is injected into the expansion lumen 115 and the internal pressure of the expansion lumen 115 exceeds a predetermined value. A part of the annular member 231 is fixed to the outer surface of the outer tube 111. For this reason, it is possible to prevent the annular member 231 from falling off the balloon catheter 100 when the knot 232 is broken.

  In the present embodiment, the annular member 231 is formed by connecting both ends of the belt-like member into an annular shape in the first state, but the configuration of the annular member 231 is the outer tube 111 in the first state. The tightening force can be applied along the outer periphery of the gas, and when the fluid F is injected into the expansion lumen 115 and the internal pressure of the expansion lumen 115 exceeds a predetermined value, the first state can be shifted to the second state. As long as it is not particularly limited. For example, the annular member 231 may be configured by an annular member that does not include the knot 232 but includes a breakable portion that can be broken when the internal pressure of the expansion lumen 115 exceeds a predetermined value. For example, the annular member 231 may be configured by a heat shrinkable tube having a fracture portion. In this case, it is preferable that the heat-shrinkable tube shrinks at a temperature lower than the melting point of the material constituting the outer tube 111 and the inner tube 112. With this configuration, the heat shrinkable tube that is the annular member 231 heats the outer tube 111 and the inner tube 112 when the heat shrinkable tube is heated to apply a tightening force along the outer periphery of the outer tube 111. It is possible to suppress the influence of. Further, when the annular member 231 is formed of a heat-shrinkable tube, the annular member 231 does not need the knot 232, and therefore the annular member 231 can be easily arranged on the balloon catheter 100.

  Moreover, it is preferable that the annular member 231 is configured not to automatically return to the first state after the transition to the second state. Thereby, after expanding the expansion part 120, the surgeon can discharge | emit the fluid F in the expansion part 120, and can contract the expansion part 120 easily.

  As described above, according to the balloon catheter 100 according to the modification of the first embodiment, the fluid adjustment unit 230 includes the annular member 231 that applies a tightening force along the outer peripheral surface of the outer tube 111 in the first state, The member 231 directly contacts the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 in the first state. Since the annular member 231 is provided on the outer peripheral side of the outer tube 111, the balloon catheter 100 can be manufactured relatively easily.

(Second Embodiment)
FIG. 5 is a view showing a balloon catheter 100 according to the second embodiment. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the balloon catheter 100 according to the second embodiment, as shown in FIG. 5B, when the fluid adjusting unit 330 is in the first state, the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 are a gap member. In the point which maintains the state contacted via 331, it differs from a 1st embodiment. Hereinafter, the balloon catheter 100 according to the second embodiment will be described in detail.

  The constituent materials of the inner tube 112 and the outer tube 111 are not limited to materials that can be heat-sealed. The inner tube 112 and the outer tube 111 are made of a material having a certain degree of flexibility. Examples of such materials include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, polyvinyl chloride resin, polyamide. Polyamide elastomer, polyester, polyester elastomer, polyurethane, fluororesin, silicone rubber, latex rubber and the like can be used.

  As shown in FIG. 5A, the gap member 331 is interposed between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 in the first state. It is comprised by the adhesion part 332 adhere | attached on the internal peripheral surface of 111. FIG. The bonding portion 332 is not particularly limited as long as it can be bonded to the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111. For example, the bonding portion 332 can be formed of an adhesive, a tape having adhesiveness on both surfaces, or the like.

  When the fluid F is injected into the expansion lumen 115 and the internal pressure of the expansion lumen 115 exceeds a predetermined value, the adhesive portion 332 is connected to the outer peripheral surface of the inner tube 112 and the inner periphery of the outer tube 111 as shown in FIG. The expanded portion 120 and the expanded lumen 115 are communicated with each other by separating the surface.

  In FIG. 5B, in the second state, the bonding portion 332 bonded to the inner peripheral surface of the outer tube 111 releases the bond with the outer peripheral surface of the inner tube 112, whereby the inner tube A state in which the outer peripheral surface 112 and the inner peripheral surface of the outer tube 111 are separated is illustrated. However, the present invention is not limited to this case. For example, the outer peripheral surface of the inner tube 112 can be obtained by releasing the adhesion between the outer peripheral surface of the outer tube 111 and the bonding portion 332 bonded to the outer peripheral surface of the inner tube 112. The surface and the inner peripheral surface of the outer tube 111 may be separated. Further, for example, the adhesive portion 332 may be broken to separate the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111.

  Note that it is preferable that the bonding portion 332 is configured not to automatically return to the first state after the transition to the second state. Thereby, after expanding the expansion part 120, the surgeon can discharge | emit the fluid F in the expansion part 120, and can contract the expansion part 120 easily.

  As described above, according to the balloon catheter 100 according to the second embodiment, in the first state, the fluid adjusting unit 330 is in contact with the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 via the gap member 331. The state is maintained, and when the fluid F is injected into the expansion lumen 115 and the internal pressure of the expansion lumen 115 exceeds a predetermined value, the state shifts from the first state to the second state. For this reason, when the fluid F is not injected into the expansion lumen 115, the inside of the shaft 110 is not pressurized, and the shaft 110 can maintain a relatively flexible state. In this state, the balloon catheter 100 can move smoothly through the living body lumen. On the other hand, by injecting the fluid F into the expansion lumen 115 so that the internal pressure of the expansion lumen 115 becomes a predetermined value or less, the inside of the shaft 110 is pressurized and the rigidity of the shaft 110 is increased while maintaining the contraction state of the expansion portion 120. Can be increased. For this reason, the force by which the surgeon pushes the shaft 110 is transmitted well to the expanded portion 120, and the pushability of the expanded portion 120 into the narrowed portion can be improved.

  In the first state, the gap member 331 is interposed between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 and adheres to the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111. An adhesive portion 332 is provided. For this reason, it is possible to close the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 without particularly limiting the constituent materials of the inner tube 112 and the outer tube 111.

(Modification of the second embodiment)
FIG. 6 is a view showing a balloon catheter 100 according to a modification of the second embodiment. In addition, about the structure similar to 1st Embodiment and 2nd Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the balloon catheter 100 according to the modification of the second embodiment, as shown in FIG. 6A, the gap member 431 is disposed between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111, The second embodiment is different from the second embodiment in that the annular member 432 is slidable along the inner tube 112. Hereinafter, the balloon catheter 100 according to a modification of the second embodiment will be described in detail.

  In the first state, the annular member 432 is disposed between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111, and contacts the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111.

  The frictional force between the annular member 432 and the outer peripheral surface of the inner tube 112 and the frictional force between the annular member 432 and the inner peripheral surface of the outer tube 111 are fluid F when the internal pressure of the expansion lumen 115 exceeds a predetermined value. Is smaller than the force pushing the annular member 432 toward the extended portion 120 side. For this reason, as shown in FIG. 6B, when the fluid F is injected into the expansion lumen 115 and the internal pressure of the expansion lumen 115 exceeds a predetermined value, it slides along the inner tube 112 toward the expansion portion 120. Is possible. For this reason, the annular member 432 is configured not to automatically return to the first state after the transition to the second state. Accordingly, the operator can easily contract the expansion portion 120 by discharging the fluid F in the expansion portion 120 after expanding the expansion portion 120.

  In the present embodiment, the annular member 432 is in contact with the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 on the arc-shaped outer surface, and the outer peripheral surface of the inner tube 112 and the inner tube 111 Since the contact area with the peripheral surface is relatively small, it is possible to slide to the extended portion 120 side more easily.

  As described above, according to the balloon catheter 100 according to the modified example of the second embodiment, the gap member 431 is disposed between the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111 in the first state. An annular member 432 that contacts the outer peripheral surface of the tube 112 and the inner peripheral surface of the outer tube 111 is provided, and the annular member 432 expands along the inner tube 112 when the internal pressure of the expansion lumen 115 exceeds a predetermined value. Slide to 120 side. Even if the annular member 432 is not adhered to the outer peripheral surface of the inner tube 112 and the inner peripheral surface of the outer tube 111, the annular member 432 is disposed on the outer periphery of the inner tube 112. Therefore, the balloon catheter 100 can be manufactured more easily.

  As described above, the balloon catheter according to the present invention has been described through a plurality of embodiments and modifications. However, the present invention is not limited only to the respective configurations described, and may be appropriately changed based on the description of the claims. Is possible.

  For example, the balloon catheter according to the present invention can be applied not only to a balloon catheter used for expanding a stenosis part but also to a balloon catheter for stent delivery in which a stent is delivered to and placed in a stenosis part. is there.

  Moreover, you may provide both the fusion | fusion part 131 which concerns on 1st Embodiment, and the annular member 231 which concerns on the modification of 1st Embodiment in the balloon catheter 100. FIG.

  In addition, the fluid adjusting unit includes the first state and the second state, and the above-described embodiment and its modified examples are applicable as long as the internal pressure of the expansion lumen exceeds a predetermined value and can be shifted from the first state to the second state. It is not limited to the configuration. For example, the fluid adjustment portion includes an engagement portion that engages the outer periphery of the inner tube and the inner periphery of the outer tube, and the engagement portion engages to form the first state, and the internal pressure of the expansion lumen When the value exceeds a predetermined value, the engagement portion may be disengaged and the second state may be entered. In addition, for example, the fluid adjusting unit may include an elastic film that is fixed to either the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tube and closes the space between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube. When the internal pressure of the expansion lumen exceeds a predetermined value, the elastic membrane is deformed, and a gap is formed between the tube and the non-fixed side. Also good.

100 balloon catheter,
110 shaft,
111 outer tube,
112 inner pipe,
115 expansion lumens,
120 balloon,
130, 230, 330, 430 Fluid adjustment part,
131 fused part,
140 hub,
231, 432 annular member,
331, 431 Gap member,
332 adhesive part,
F fluid,
N stenosis,
W Guide wire.

Claims (5)

A flexible elongate shaft with an outer tube having a lumen and an inner tube disposed in the lumen of the outer tube;
A distal end portion is fixed to the distal end portion of the inner tube, and a proximal end portion is fixed to the distal end portion of the outer tube, and an expansion portion that can be expanded and contracted as fluid flows in and out, and
Formed between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, and an expansion lumen through which the fluid can flow;
A fluid adjustment unit that controls movement of the fluid in the expansion lumen;
The fluid adjustment unit includes a first state in which a space between the expansion lumen and the expansion portion is closed, and a second state in which the expansion lumen and the expansion portion are communicated with each other.
In the first state, the fluid adjusting unit maintains a state in which the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube are in direct contact with each other via a gap member, When the fluid is injected and the internal pressure of the expansion lumen exceeds a predetermined value, the balloon catheter shifts from the first state to the second state. In the first state, the fluid adjustment portion includes a fusion portion in which the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube are fused.
The balloon catheter according to claim 1, wherein the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube are in direct contact with each other in the first state by the fusion part. The fluid adjustment unit includes an annular member that applies a tightening force along an outer peripheral surface of the outer tube in the first state,
The balloon according to claim 1, wherein the annular member directly contacts the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube in the first state. catheter.   In the first state, the gap member is interposed between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, and the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube. The balloon catheter according to claim 1, further comprising an adhesive portion that adheres to the balloon catheter. In the first state, the gap member is disposed between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, and the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube. An annular member in contact with
2. The balloon catheter according to claim 1, wherein the annular member slides along the inner tube toward the expansion portion when an internal pressure of the expansion lumen exceeds the predetermined value.