JP2019129892A - Balloon catheter - Google Patents

Abstract

To provide a balloon catheter capable of contracting excellently an expanded balloon.SOLUTION: A balloon catheter 10 has a long-sized shaft 40 inserted into a biological lumen, a balloon 30 including a proximal diameter reduction part 32 provided on the distal side of the shaft 40, expandable and contractible in a radial direction, and reducing a diameter toward a connection part to the shaft 40 on the end part in the axial direction, and a film body 50 fixed to the proximal diameter reduction part 32 and the shaft 40.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a balloon catheter.

  In recent years, a balloon catheter has been used to improve a lesion (stenosis) occurring in a living body lumen. A balloon catheter usually includes a long shaft and a balloon that is provided on the distal end side of the shaft and is expandable in the radial direction. By expanding the deflated balloon after reaching a target location in the body via a thin living body lumen, the lesioned part can be expanded.

  A balloon that is folded is difficult to return to its fully folded state after expansion. For this reason, when the balloon that has been deflated and then deflated is drawn into the sheath or guiding catheter, the resistance of the reduced diameter portion on the proximal side of the balloon increases. For this reason, the workability | operativity of balloon collection | recovery falls.

  For this reason, for example, Patent Document 1 describes a balloon catheter in which fins for re-wrapping a balloon using blood flow are provided on the balloon.

  For example, Patent Document 2 describes a balloon catheter including an auxiliary part that can be expanded and contracted together with a balloon. When the shape of the balloon that is deflated after being expanded is disturbed, the diameter of the balloon can be reduced using the auxiliary portion and collected into the guiding catheter.

Special table 2010-525880 gazette Japanese Patent Laid-Open No. 2006-016210

  Since the balloon catheter described in the cited document 1 utilizes the force of fluid, it may be difficult to apply a desired force to the expanded balloon with fins. Moreover, since the auxiliary | assistant part is not being fixed to the balloon in the balloon catheter of the cited reference 2, it may be difficult to make a desired force act on the expanded balloon with an auxiliary | assistant part.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a balloon catheter that can satisfactorily deflate an expanded balloon.

  A balloon catheter according to the present invention that achieves the above object is provided with a long shaft inserted into a living body lumen, and provided on the distal side of the shaft and can be expanded and contracted in the radial direction. A balloon having a diameter-reducing portion that is reduced in diameter toward a connecting portion with the shaft; and a film body fixed to the diameter-reducing portion and the shaft.

  The balloon catheter configured as described above can cause the expanded balloon to be deflated by being guided to a good deflated state by the membrane body. For this reason, it becomes easy to draw the balloon into the tube body, and workability is improved.

  The film body may be bent in the circumferential direction along the shape of the shaft. Thereby, when the balloon is deflated after being expanded, the balloon can be folded into a favorable deflated state by returning the membrane body to the original bent shape.

  The film body may connect a reduced diameter portion on the proximal side of the balloon and the shaft on the proximal side of the balloon. Thereby, since the proximal portion of the balloon is satisfactorily folded by the membrane body, it becomes easy to draw the balloon from the proximal side to the tube body, and workability is improved.

  A plurality of the film bodies may be provided in the circumferential direction of the balloon. Accordingly, the film can be folded uniformly by applying a force to a plurality of locations in the circumferential direction of the balloon by the film body.

  In a state where the balloon is expanded, the film body may be inclined in a circumferential direction from a fixed position with respect to the shaft toward a fixed position with respect to the reduced diameter portion. Thereby, the film body can be favorably shaped into a shape bent in the circumferential direction along the shape of the shaft. Thereby, when the balloon is deflated after being expanded, the balloon can be folded into a favorable deflated state by favorably returning the film body to the original bent shape. Therefore, it becomes easier to draw the balloon into the tube body, and the workability is further improved.

  The balloon may have a plurality of blade portions projecting radially outward in an expanded state, and the film body may be provided corresponding to each of the blade portions. Thereby, a force can be applied to each of the blade portions of the balloon by the film body, so that the balloon can be folded well.

  The film body may be formed of a stretchable material and stretched when the balloon is expanded. Thereby, when the balloon is expanded, the film body expands, and a pulling force from the film body acts on the balloon. For this reason, when the balloon is deflated, the balloon is pulled by the film body that is contracted by the restoring force, so that the balloon can be folded well.

It is a top view which shows the balloon catheter which concerns on 1st Embodiment. It is sectional drawing which follows the AA line of FIG. It is sectional drawing of the distal part of the balloon catheter which expanded the balloon. It is a figure which shows the balloon of a contracted state, (A) is a top view, (B) is sectional drawing which follows the BB line of (A). It is a figure which shows the balloon of an expanded state, (A) is a top view, (B) is sectional drawing which follows the CC line of (A). It is a top view which shows the distal part of the balloon catheter which concerns on 2nd Embodiment, (A) shows the contracted state of a balloon, (B) shows the expanded state of a balloon. It is a figure which shows the distal part of the balloon catheter which concerns on 3rd Embodiment, (A) is a top view at the time of expansion of a balloon, (B) is sectional drawing which follows the DD line | wire of (A). It is sectional drawing which shows the balloon of a contracted state.

Embodiments of the present invention will be described below with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.
<First Embodiment>

  As shown in FIGS. 1 to 3, the balloon catheter 10 according to the first embodiment of the present invention is a device that is inserted into a stenosis part of a living body lumen such as a blood vessel to spread the stenosis part. In this specification, the side to be inserted into the living body lumen of the balloon 30 catheter 10 is referred to as “distal side”, and the proximal side for operation is referred to as “proximal side”.

  The balloon 30 catheter 10 includes a long shaft 40, a balloon 30 provided at a distal portion of the shaft 40, and a membrane body 50 fixed to the balloon 30 and the shaft 40. The balloon catheter 10 further includes a drug layer 20 provided on the surface of the balloon 30 and a hub 46 fixed to the proximal end of the shaft 40.

  The shaft 40 includes an outer tube 41 that is a tube having an open distal end and a proximal end, and an inner tube 42 that is a tube disposed inside the outer tube 41. The inner tube 42 is housed in the hollow interior of the outer tube 41, and the shaft 40 has a double tube structure at the distal portion. The hollow interior of the inner tube 42 is a guide wire lumen 44 through which the guide wire is inserted. In addition, an expansion lumen 43 through which the expansion fluid of the balloon 30 flows is formed inside the hollow of the outer tube 41 and outside the inner tube 42. The inner tube 42 opens to the outside at the side opening 45. The inner tube 42 protrudes further to the distal side than the distal end of the outer tube 41. A distal tip, which is a separate member, may be provided at the distal portion of the inner tube 42.

  The balloon 30 includes a straight portion 31 formed at the central portion in the axial direction, a proximal reduced diameter portion 32 located on the proximal side of the straight portion 31, and a distal reduced diameter located on the distal side of the straight portion 31. Part 33. The straight portion 31 has a cylindrical shape with substantially the same outer diameter when expanded. The proximal diameter-reduced portion 32 has an outer diameter that gradually decreases from the straight portion 31 toward the proximal side. The outer diameter of the distal reduced diameter part 33 gradually decreases from the straight part 31 toward the distal side.

  The drug layer 20 is a layer that contains a drug that acts on the stenosis that is expanded by the balloon 30. The drug layer 20 is formed on the surface of the straight portion 31. The drug may be a water-soluble drug, but is preferably a water-insoluble drug. The water-insoluble drug means a drug that is insoluble or hardly soluble in water. Specifically, the solubility in water is less than 5 mg / mL at pH 5-8. Its solubility may be less than 1 mg / mL and even less than 0.1 mg / mL. Water-insoluble drugs include fat-soluble drugs.

  Examples of some preferred water-insoluble drugs include immunosuppressants, such as cyclosporines including cyclosporine, immunoactive agents such as rapamycin, anticancer agents such as paclitaxel, antiviral or antibacterial agents, anti-neoplastic agents, Analgesics and anti-inflammatory agents, antibiotics, antiepileptics, anxiolytics, antiparalytic agents, antagonists, neuron blocking agents, anticholinergics and cholinergic agents, antimuscarinic and muscarinic agents, antiadrenergic agents, Contains antiarrhythmic, antihypertensive, hormonal and nutritional agents.

  The water-insoluble drug is preferably at least one selected from the group consisting of rapamycin, paclitaxel, docetaxel and everolimus. In the present specification, rapamycin, paclitaxel, docetaxel, and everolimus include analogs and / or derivatives thereof as long as they have similar medicinal effects. For example, paclitaxel and docetaxel are in an analog relationship. Rapamycin and everolimus are in a derivative relationship. Of these, paclitaxel is more preferred. An additive (excipient) may be added to the drug.

In the balloon 30, a balloon fusion part 34 located at the proximal end of the proximal diameter reducing part 32 is fused to the distal part of the outer tube 41. In the balloon 30, a balloon fusion portion 35 located at the distal end of the distal diameter-reduced portion 33 is fused to the distal portion of the inner tube 42. The method for fixing the balloon 30 to the outer tube 41 and the inner tube 42 is not limited to fusion, and may be bonded, for example. Thereby, the inside of the balloon 30 communicates with the expansion lumen 43. The balloon 30 can be expanded by injecting the expansion fluid into the balloon 30 through the expansion lumen 43. The expansion fluid may be a gas or a liquid. For example, a gas such as helium gas, CO ₂ gas, O ₂ gas, N ₂ gas, Ar gas, air, mixed gas, or a liquid such as physiological saline or contrast medium is used. Can do.

  The balloon 30 has a plurality of blade portions 37 that are shaped so as to protrude in the radial direction. The wing | blade part 37 can be laid down and laid down in the circumferential direction. The blade portion 37 is formed by a fold extending in the substantially axial direction of the balloon 30. The length of the blade portion 37 in the major axis direction does not exceed the length of the balloon 30. The number of the blade | wing part 37 is not specifically limited, For example, although it is 1-7 sheets, in this embodiment, it is three sheets. The plurality of blade portions 37 are preferably arranged uniformly in the circumferential direction of the balloon 30, but are not limited thereto.

  Although the axial length of the balloon 30 is not particularly limited, it is preferably 5 to 500 mm, more preferably 10 to 300 mm, and still more preferably 20 to 200 mm. Although the outer diameter at the time of expansion of the balloon 30 is not particularly limited, it is preferably 1 to 10 mm, more preferably 2 to 8 mm.

  It is preferable that the balloon 30 has a certain degree of flexibility so that it can be expanded when it reaches a blood vessel, a tissue, or the like, and can release a drug on its surface. Specifically, it is made of metal or resin. It is preferable that at least the surface of the balloon 30 is made of resin. The constituent material of at least the surface of the balloon 30 is, for example, a polyolefin such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these, or soft polychlorinated Vinyl resins, polyamides, polyamide elastomers, nylon elastomers, polyesters, polyester elastomers, polyurethanes, thermoplastic resins such as fluorine resins, silicone rubbers, latex rubbers and the like can be used. Among these, polyamides are preferable.

  The hub 46 is formed with a proximal opening 47 that functions as a port that communicates with the expansion lumen 43 of the outer tube 41 and allows the expansion fluid to flow in and out.

  At least one (three in this embodiment) film body 50 is provided along the circumferential direction of the balloon 30 and the shaft 40. Each film body 50 includes a first joint portion 51 joined to the proximal diameter-reduced portion 32 and a second joint portion 52 joined to the outer tube 41 of the shaft 40. The 1st junction part 51 and the 2nd junction part 52 are joined by means, such as heat sealing | fusion and adhesion | attachment, with respect to joining object. The first joint portion 51 is fixed at a substantially linear position along the axial direction on the outer peripheral surface of the proximal reduced diameter portion 32. The second joint portion 52 is fixed at a substantially linear position along the axial direction on the outer surface of the balloon fusion portion 34 and the outer tube 41 located on the proximal side of the balloon fusion portion 34. Each membrane body 50 has an outer edge portion 53 that is separated from the outer tube 41 and the balloon 30. The 1st junction part 51, the 2nd junction part 52, and the outer edge part 53 form a substantially triangular shape. Each film body 50 is formed in a substantially triangular shape in which the first joint 51 and the second joint 52 are in contact at an obtuse angle. The balloon fusion part 34 is a part of the shaft 40 by being fixed to the outer tube 41. Therefore, when the balloon fusion part 34 is long in the axial direction, the second joining part 52 may be joined only to the balloon fusion part 34 that is a part of the shaft 40 without being joined to the outer tube 41. . The film body 50 may be formed integrally with the balloon 30.

  The plurality of film bodies 50 are uniformly arranged in the circumferential direction. The number of the plurality of film bodies 50 matches the number of the blade portions 37. Each film body 50 is provided corresponding to the blade portion 37. That is, one film body 50 is disposed on the proximal side of each blade portion 37. Two or more film bodies 50 may be provided on the proximal side of each blade portion 37. The distal portion of each membrane 50 is preferably coincident with or close to the top of the blade 37, but is not limited thereto. Moreover, the blade | wing part 37 in which the film body 50 is not provided in the proximal side may exist. The material applicable to the balloon 30 described above can be applied as the constituent material of the film body 50. Note that the constituent material of the film body 50 may be the same as or different from the constituent material of the balloon 30. Although the thickness of the film body 50 is not specifically limited, For example, it is larger than the thickness of the balloon 30. Thereby, the bending rigidity of the film body 50 is increased, and the function of guiding the folding of the balloon 30 is increased.

  The film body 50 is shaped together with the blade portion 37 when the blade portion 37 of the balloon 30 is laid down so as to be wound around the outer peripheral surface of the inner tube 42. Thereby, the film body 50 is bent and shaped so as to be wound along the outer peripheral surface of the inner tube 42 or the outer tube 41. The shaping is performed by heating the blade portion 37 and the film body 50 before, during or after winding.

  Next, the operation of the balloon catheter 10 according to the first embodiment will be described.

  When the balloon 30 is expanded to expand the stenosis, as shown in FIG. 4, the balloon catheter 10 with the balloon 30 contracted is inserted into the living body lumen. Next, a predetermined amount of expansion fluid is injected from the proximal opening 47 of the hub 46 using an indeflator or a syringe. As a result, the expansion fluid is sent into the balloon 30 through the expansion lumen 43. Thereby, the folded balloon 30 is expanded as shown in FIG. When the balloon 30 is expanded, the bending of the membrane body 50 that is shaped to wrap around the balloon 30 and the shaft 40 is extended.

  After the stenosis is expanded, the expansion fluid inside the balloon 30 is sucked and discharged from the proximal opening 47 of the hub 46. Thereby, the balloon 30 is deflated. At this time, since the balloon 30 is thin and flexible and easily deformed, it is difficult to return to the original folded state. However, since the film body 50 is bent along the shape of the outer peripheral surface of the shaft 40, the film body 50 is restored to the original bent shape. For this reason, the membrane body 50 guides the proximal portion of the balloon 30 to the original folded shape, and causes the balloon 30 to contract well. Thereafter, the balloon 30 is accommodated in a tubular body such as a sheath or a guiding catheter that accommodates the shaft 40 on the proximal side of the balloon 30. At this time, since the balloon 30 is accommodated in the tubular body from the membrane body 50 side, the balloon 30 is favorably accommodated in the tubular body. Thereafter, the balloon catheter 10 is removed from the living body, and the procedure is completed.

  As described above, the balloon catheter 10 according to the first embodiment is provided with the long shaft 40 inserted into the living body lumen and the distal side of the shaft 40 and can be expanded and contracted in the radial direction. A balloon 30 having a proximal diameter-reduced portion 32 that is diameter-reduced toward a connecting portion with the shaft 40 at an axial end, and a membrane body 50 fixed to the proximal diameter-reduced portion 32 and the shaft 40. Have.

  With the balloon catheter 10 configured as described above, the expanded balloon 30 can be guided and contracted by the membrane body 50 into a favorable contracted state. For this reason, it becomes easy to draw the balloon 30 into the tube body, and workability is improved.

  The film body 50 is bent along the shape of the shaft 40 in the circumferential direction. Thereby, when the balloon 30 is deflated after being expanded, the film body 50 returns to the original bent shape, so that the balloon 30 can be folded into a favorable deflated state.

  The membrane body 50 connects the proximal diameter-reduced portion 32 of the balloon 30 and the shaft 40 on the proximal side of the balloon 30. Thereby, since the proximal portion of the balloon 30 is satisfactorily folded by the membrane body 50, the balloon 30 can be easily pulled into the tube body from the proximal side, and workability is improved.

  A plurality of film bodies 50 are provided in the circumferential direction of the balloon 30. Thereby, the film body 50 can apply force to a plurality of locations in the circumferential direction of the balloon 30 to fold the balloon 30 uniformly.

The balloon 30 has a plurality of blade portions 37 that protrude radially outward in an expanded state, and a film body 50 is provided corresponding to each of the blade portions 37. Thereby, the film body 50 can fold the balloon 30 satisfactorily by applying a force to each of the blade portions 37 of the balloon 30. Moreover, since the film body 50 is provided corresponding to the top part of the blade | wing part 37 of the balloon 30, the balloon 30 can be folded more favorably.
<Second Embodiment>

  As shown in FIG. 6, the balloon catheter 60 according to the second embodiment of the present invention is different from the first embodiment only in the structure of the membrane body 70. In addition, the same code | symbol is attached | subjected to the site | part which has a function similar to 1st Embodiment, and description is abbreviate | omitted.

  In the balloon catheter 60 according to the second embodiment, the membrane body 70 is formed of a stretchable material having high stretchability. The film body 70 is fixed to the proximal reduced diameter portion 32 by the first fixing portion 71, and is fixed to the balloon fusion portion 34 and the outer tube 41 by the second fixing portion 72. Each film body 70 has an outer edge portion 73 that is separated from the outer tube 41 and the balloon 30. As shown in FIG. 6A, the film body 70 is fixed to the balloon 30 and the outer tube 41 so as to have a natural shape that is not substantially elongated in a state in which the balloon 30 is deflated. The constituent material of the film body 70 is not particularly limited. For example, various rubber materials such as natural rubber, silicone rubber, butyl rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, polyurethane, polyester, polyamide, Highly elastic materials such as various thermoplastic elastomers such as olefins and styrenes, or mixtures thereof can be suitably used.

  Next, the operation of the balloon catheter 60 according to the second embodiment will be described.

  When the balloon 30 is expanded, as shown in FIG. 6B, the film body 70 that is in a substantially natural state with the balloon 30 contracted expands. When the balloon 30 is expanded, the blade portion 37 expands while rotating around the shaft 40. For this reason, the direction in which the film body 70 extends is the radially outer side and the circumferential direction of the balloon 30 and the shaft 40. Therefore, as shown in FIG. 6A, when the balloon 30 is deflated, the blade portion 37 is deflated by its own restoring force. At this time, the blade portion 37 is pulled by the film body 70 and contracts radially inward and circumferentially. For this reason, the proximal portion of the blade portion 37 of the balloon 30 is guided by the contracting film body 70 and is folded so as to wind the outer periphery of the shaft 40.

As described above, the film body 70 in the second embodiment is formed of a stretchable material and extends when the balloon 30 is expanded. As a result, when the balloon 30 is expanded, the film body 70 expands, and a pulling force from the film body 70 acts on the balloon 30. For this reason, when the balloon 30 is deflated, the balloon 30 is pulled by the film body 70 that is deflated by its own restoring force, and the balloon 30 can be folded well.
<Third Embodiment>

  As shown in FIG. 7, the balloon catheter 80 according to the third embodiment of the present invention differs from the first embodiment only in the structure of the membrane body 90. In addition, the same code | symbol is attached | subjected to the site | part which has a function similar to 1st Embodiment, and description is abbreviate | omitted.

  In the balloon catheter 80 according to the third embodiment, the film body 90 when the balloon 30 is in an expanded state is inclined at an angle θ in the circumferential direction with respect to the normal direction of the outer peripheral surface of the shaft 40. The angle θ is not particularly limited, but is preferably 30 to 60 degrees. The methods of tilting the plurality of film bodies 90 are the same.

  Next, the operation of the balloon catheter 80 according to the third embodiment will be described.

  When the balloon 30 is expanded, as shown in FIG. 7, the film body 90 is inclined at an angle θ in the circumferential direction with respect to the normal direction of the outer peripheral surface of the shaft 40. Next, as shown in FIG. 8, the blade portion 37 of the balloon 30 is laid on the outer peripheral surface of the shaft 40 in the direction in which the film body 90 is inclined. Then, the film body 90 is folded so as to wind the outer periphery of the shaft 40 together with the blade portion 37. Further, the blade 37 and the film body 90 are heated before, during or after the blade 37 and the film 90 are wound. Thereby, the balloon 30 and the film body 90 are bent and shaped so as to be wound along the outer peripheral surface of the shaft 40.

  As described above, in a state where the balloon 30 is expanded, the film body 90 is inclined in the circumferential direction from the fixed position with respect to the shaft 40 toward the fixed position with respect to the proximal reduced diameter portion 32. That is, the film body 90 is already inclined in the circumferential direction before shaping. Furthermore, the film body 90 can be formed longer than the case where the angle θ = 0 by tilting the film body 90 at an angle θ in the circumferential direction. For this reason, the film body 90 can be favorably shaped into a shape bent in the circumferential direction along the shape of the shaft 40. Thereby, when the balloon 30 is deflated after being expanded, the film body 90 is favorably returned to the original bent shape, so that the balloon 30 can be folded into a favorable deflated state. Therefore, it becomes easier to draw the balloon 30 into the tube body, and the workability is further improved.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, the balloon catheters 10 and 60 are a rapid exchange type, but may be an over-the-wire type.

  In the first embodiment, the absence of a film body on the distal side of the balloon 30 prevents the length of the balloon catheter 10 from increasing on the distal end side of the balloon 30 and thus reducing the operability. Yes. However, the membrane body may be provided on the distal side of the balloon 30. That is, the membrane body may be fixed to the distal reduced diameter portion 33 and the inner tube 42.

10, 60, 80 Balloon catheter 30 Balloon 32 Proximal diameter reduction part 33 Distal diameter reduction part 37 Blade part 40 Shaft 50, 70, 90 Membrane 51, 71 First joint part 52, 72 Second joint part

Claims (7)

An elongated shaft that is inserted into the body lumen;
A balloon provided on a distal side of the shaft and capable of expanding and contracting in a radial direction, and having a reduced diameter portion that decreases in diameter toward a connecting portion with the shaft at an axial end portion;
A balloon catheter having the reduced diameter portion and a membrane body fixed to the shaft.   The balloon catheter according to claim 1, wherein the membrane body is bent in a circumferential direction along the shape of the shaft.   The balloon catheter according to claim 1, wherein the membrane body connects a reduced diameter portion on the proximal side of the balloon and the shaft on the proximal side of the balloon.   The balloon catheter according to claim 1, wherein a plurality of the membrane bodies are provided in a circumferential direction of the balloon.   The balloon catheter according to any one of claims 1 to 4, wherein the membrane body is inclined in a circumferential direction from a fixed position with respect to the shaft toward a fixed position with respect to the reduced diameter portion in a state where the balloon is expanded. . The balloon has a plurality of blade portions projecting radially outward in an expanded state,
The balloon catheter according to any one of claims 1 to 5, wherein the film body is provided corresponding to each of the blade portions.   The balloon catheter according to any one of claims 1 to 6, wherein the film body is formed of a stretchable material and extends when the balloon is expanded.

Images