JP2018068529A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter which can reliably shrink a balloon after expanding it and makes it easy to collect balloons after use.SOLUTION: A balloon catheter 10 has: a long shaft part 20; a balloon 30 which is folded on an outer peripheral surface of a distal part of the shaft part 20 and can expand by fluid being flown inside; and at least one ring-shaped shrink auxiliary part 60 which encircles a part of an axial direction on an outer peripheral surface of the folded balloon 30 in a peripheral direction and has greater stretchability than the balloon 30. At least one part of the peripheral direction of the shrink auxiliary part 60 can slide with respect to the balloon 30, and in the state that the balloon 30 is expanded, the shrink auxiliary part 60 generates a shrinking force by expanding longer than natural length.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a balloon catheter having an inflatable balloon.

  In recent years, a balloon catheter has been used to improve a lesion (stenosis) occurring in a living body lumen. The balloon catheter usually includes a long shaft portion and a balloon that is provided on the distal end side of the shaft portion 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.

  By the way, there is a high possibility that the balloon after being expanded is disordered when contracted and does not return to the shape before expansion. When the shape of the balloon is disturbed, the outer diameter of the balloon increases, and it may be difficult to draw it into a sheath or guiding catheter. For this reason, Patent Document 1 describes a balloon in which the flexibility of a part of the balloon is increased and the rigidity of the part is further increased so that the balloon is easily contracted into a desired shape after being expanded. This balloon is easily folded into a desired shape with a portion having increased flexibility as a trough and a portion having increased rigidity as a crest.

International Publication No. 2008/060750

  Even in the case of the balloon described in Patent Document 1, for example, when the balloon is long in the axial direction, the shape tends to vary depending on the position of the balloon in the axial direction, and it is difficult to reliably deflate the balloon.

  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 be reliably contracted after the balloon is expanded and can be easily recovered after use.

  A balloon catheter that achieves the above-described object is provided with a long shaft portion, a balloon that is folded on an outer peripheral surface of a distal portion of the shaft portion, and a balloon that is expandable by flowing a fluid therein. At least one ring-shaped contraction assisting portion that surrounds a part of the outer circumferential surface of the balloon in the circumferential direction and has higher elasticity than the balloon, and at least one of the contraction assisting portions in the circumferential direction. The part is slidable with respect to the balloon, and in a state where the balloon is expanded, the contraction assisting part extends longer than the natural length and generates contraction force.

  In the balloon catheter configured as described above, since the deflation assisting portion extends when the balloon is expanded, the expansion of the balloon is not hindered by the deflation assisting portion. And since a contraction force generate | occur | produces in a contraction assistance part when a balloon expands, if a fluid is discharged | emitted from a balloon, a contraction assistance part will shrink | contract. Thus, the balloon can be reliably deflated by the deflation assisting part, and the used balloon can be easily collected.

  The contraction assisting part may be fixed to a part of the outer peripheral surface of the balloon in the circumferential direction. Thereby, falling off from the balloon of a contraction auxiliary part can be controlled. In addition, when the balloon is expanded and contracted, the portion of the contraction assisting portion that is not fixed to the balloon can slide and slide and expand and contract satisfactorily.

  A plurality of the contraction assisting units may be provided on the outer peripheral surface of the balloon along the axial direction. Thereby, the whole of the balloon in the axial direction can be effectively contracted by the contraction assisting portion. For this reason, for example, even when the balloon is long in the axial direction, the entire axial direction of the balloon can be effectively contracted.

  In the state where the balloon is folded, the contraction assisting part may extend longer than the natural length. Thereby, it can suppress that a contraction auxiliary | assistant part loosens with the outer peripheral surface of the balloon of the folded state. Therefore, the contraction assisting part can be prevented from being caught by other parts, and the contraction assisting part can be prevented from falling off from the balloon during transportation. In addition, since the contraction force of the contraction assisting portion acts on the balloon, the balloon before expansion can be maintained with a small diameter, and the balloon once expanded can be contracted with a small diameter.

It is a top view which shows the balloon catheter which concerns on this embodiment. It is sectional drawing which shows the distal part of the balloon catheter of the state which the balloon contracted. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which shows the distal part of the balloon catheter of the state which the balloon expanded. It is sectional drawing which follows the BB line of FIG. It is a top view which shows the distal part of the balloon catheter which the balloon contracted after expansion.

  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.

  The balloon catheter 10 according to the present embodiment is a device that is used by being percutaneously inserted into a living body lumen, and for expanding the narrowed portion of the living body lumen. The balloon catheter 10 is a so-called rapid exchange type catheter, and as shown in FIGS. 1 to 3, a long shaft portion 20, a balloon 30 provided at a distal end portion of the shaft portion 20, and a shaft It has a hub 40 fixed to the base end of the portion 20, a distal tip 50 located at the forefront of the shaft portion 20, and a contraction assisting portion 60 attached to the balloon 30. In this specification, the side of the balloon catheter 10 that is inserted into the living body lumen is referred to as the “front end side”, and the proximal side that is operated is referred to as the “base end side”.

  The shaft portion 20 includes a tubular proximal shaft 21 whose proximal end is fixed to the hub 40, a tubular intermediate shaft 22 that covers the distal end of the proximal shaft 21, and a tubular distal end provided on the distal side of the intermediate shaft 22. A shaft 23 and a tubular inner tube 24 disposed inside the tip shaft 23 are provided. An expansion lumen 25 through which an expansion fluid for expanding the balloon 30 flows is formed inside the proximal shaft 21, the intermediate shaft 22, and the distal shaft 23.

  The inner tube 24 passes through the tip shaft 23 and the balloon 30 coaxially. The distal end portion of the inner tube 24 extends in the distal direction from the distal end of the balloon 30 and is joined to the distal end side of the balloon 30 while maintaining liquid tightness. A tubular tip 50 is fixed to the tip of the inner tube 24. The tip 50 is a flexible member for reducing the burden on the living tissue that strikes in the living body. The proximal end of the inner tube 24 is fixed to a part of the intermediate shaft 22 in the outer circumferential direction (side port formed on the side surface) while maintaining liquid tightness. The proximal end opening of the inner tube 24 is exposed to the outside of the intermediate shaft 22 to form a proximal end side opening 27 of the guide wire lumen 26. An internal space from the distal end side opening 51 to the proximal end side opening 27 formed in the distal tip 50 is a guide wire lumen 26. The guide wire is inserted into the inner tube 24 with the distal end side opening 51 as an inlet and the proximal end side opening 27 as an outlet. The proximal opening 27 may be provided not on the intermediate shaft 22 but on the proximal shaft 21 or the distal shaft 23, and is provided on a boundary portion (joint portion) between the intermediate shaft 22 and the distal shaft 23. Also good.

  The hub 40 includes a hub opening 41 that functions as a port that communicates with the expansion lumen 25 of the shaft portion 20 and allows the expansion fluid to flow in and out.

  The balloon 30 is a part that expands the stenosis by expanding. The outer surface of the balloon 30 may be coated with a drug for suppressing stenosis. Alternatively, a stent that is plastically deformed by the expansion of the balloon 30 and is placed in the stenosis may be placed on the outer surface of the balloon 30. The distal end side of the balloon 30 is joined to the outer wall surface of the inner tube 24 while maintaining liquid tightness. The proximal end side of the balloon 30 is joined to the outer wall surface of the distal end portion of the distal shaft 23 while maintaining liquid tightness. Therefore, the inside of the balloon 30 communicates with the expansion lumen 25 formed in the shaft portion 20, and the expansion fluid can flow from the proximal end side through the expansion lumen 25. The balloon 30 expands by inflow of the expansion fluid, and contracts by discharging the inflow expansion fluid.

  The balloon 30 has a plurality of protrusions 31 that protrude outward in the radial direction, for example, by blow molding or the like. The balloon 30 having the protruding portion 31 can be formed by, for example, blow molding in which a tube serving as a material is heated in a mold and pressed from the inside so as to swell with a fluid and pressed against the mold. The method for forming the balloon 30 is not particularly limited. Although the number of the protrusions 31 is four in the present embodiment, it may be one or more and can be set as appropriate. Moreover, the balloon 30 does not need to be provided with a protrusion as long as it can be folded. The protrusions 31 are preferably provided at equal intervals in the circumferential direction of the balloon 30, but may not be provided at equal intervals. In a contracted state before use, the protruding portion 31 of the balloon 30 is folded so as to wrap around the outer peripheral surface of the inner tube 24 in the circumferential direction.

  The constituent material of the balloon 30 is preferably formed of a material having a certain degree of flexibility. Examples of such a material include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer. Polymers, ionomers, polyolefins such as mixtures of two or more of these, soft polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, fluororesins and other thermoplastic resins, silicone rubbers, latex rubbers, etc. Can be used.

  The contraction assisting part 60 is a ring-shaped member surrounding the outer peripheral surface of the balloon 30 in a folded state. At least a part of the deflation assisting part 60 is slidable with respect to the outer peripheral surface of the balloon 30 without being folded together with the balloon 30. The contraction assisting part 60 has higher stretchability than the balloon 30. For this reason, when the balloon 30 is expanded and contracted, the contraction assisting part 60 can be stretched by the material itself being stretched, and can be contracted to the original shape. Two contraction assisting portions 60 are provided at an interval in the axial direction of the balloon 30. In addition, the shrinkage | contraction assistance part 60 may be one, and may be three or more. Each contraction assisting part 60 is fixed to the outer peripheral surface of the balloon 30 at one or more locations in the circumferential direction. The shrinkage assisting part 60 and the fixing part 61 of the balloon 30 are formed by, for example, heat fusion or adhesion. The fixing portion 61 is provided on the outer peripheral surface of the balloon 30 in a folded state exposed to the outside. For example, one fixing portion 61 to which each shrinkage assisting portion 60 is fixed is provided on each of the folded protruding portions 31. In addition, the fixing | fixed part 61 to which each shrinkage | contraction auxiliary | assistant part 60 is fixed does not need to be provided in each protrusion part 31 one each.

  The peripheral length of the inner peripheral surface of the contraction assisting portion 60 in the natural state before being attached to the balloon 30 is smaller than the peripheral length of the balloon 30 in the folded state. As a result, the contraction assisting part 60 is arranged on the outer peripheral surface of the folded balloon 30, whereby the contraction assisting part 60 is extended to some extent, and the contraction force of the contraction assisting part 60 acts on the balloon 30. For this reason, the contraction assisting part 60 is not loosely disposed on the outer peripheral surface of the balloon 30. Further, since the contraction force acts on the balloon 30, the balloon 30 can be maintained with a small diameter. Note that the circumferential length of the inner peripheral surface of the contraction assisting portion 60 in the natural state before being attached to the balloon 30 may be equal to or somewhat larger than the circumferential length of the balloon 30 in the folded state. In this case, the contraction assisting portion 60 is arranged on the outer peripheral surface of the balloon 30 to restrict the contraction force of the contraction assisting portion 60 from acting on the folded balloon 30, and the shape of the balloon 30 is used until it is used. And maintain the state properly.

  The constituent material of the contraction assisting part 60 is preferably a material having higher elasticity than the balloon 30, for example, an elastic material. As a constituent material of the shrinkage assisting part 60, for example, natural rubber such as latex, silicone rubber, urethane rubber, ethylene-propylene-diene rubber, nitrile rubber, fluorine rubber, acrylic rubber, or other synthetic rubber can be used.

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

  In the state before use, the balloon catheter 10 is provided with a ring-shaped contraction assisting portion 60 on the outer peripheral surface of the folded balloon 30 as shown in FIGS. The contraction assisting part 60 extends longer than the natural length, is stretched to some extent, and is disposed on the outer peripheral surface of the balloon 30. For this reason, it can suppress that the shrinkage | contraction auxiliary | assistant part 60 does not slack on the outer peripheral surface of the balloon 30, and can be caught with another site | part, and can suppress falling out of the balloon 30 at the time of conveyance. Further, since the contraction force of the contraction assisting part 60 acts on the balloon 30, the balloon 30 can be maintained with a small diameter. For this reason, the balloon 30 can be satisfactorily inserted into a thin living body lumen. Moreover, since the shrinkage assisting part 60 is fixed to the balloon 30 by a fixing part 61 provided on a part of the outer peripheral surface of the balloon 30 in the circumferential direction, the dropout in vivo is suppressed. When the balloon 30 is expanded and contracted, the portion of the contraction assisting unit 60 that is not fixed to the balloon 30 can be satisfactorily expanded and contracted.

  When the balloon 30 is disposed at a target position such as a stenosis part in a living body lumen and then fluid is supplied from the hub opening 41 to the inside of the balloon 30 through the expansion lumen 25, as shown in FIGS. The folded protrusion 31 expands and the balloon 30 expands. When the balloon 30 is expanded, the contraction assisting portion 60 surrounding the outer peripheral surface of the balloon 30 expands and expands together with the balloon 30. The balloon 30 is greatly expanded while a strong pressing force is applied to the contact target by opening the folded portion. On the other hand, the contraction assisting part 60 is expanded by expanding the material without hindering the expansion of the balloon 30. Since the deflation assisting part 60 can be extended, the expansion of the balloon 30 is not hindered by the deflation assisting part 60. At this time, by providing the fixing portions 61 in the respective protruding portions 31 arranged in the circumferential direction, when the balloon 30 is expanded, the entire circumferential direction of the contraction assisting portion 60 can be expanded substantially uniformly. For this reason, the contraction force of the contraction assisting part 60 acting on each protrusion 31 of the balloon 30 is also substantially uniform, and the balloon 30 can be appropriately expanded. In addition, since the contraction assisting part 60 is partially provided in a part of the outer peripheral surface of the balloon 30 in the axial direction, the balloon 30 can be brought into contact with the inner surface of the living tissue. For this reason, for example, when the drug is coated on the outer surface of the balloon 30, the drug can be brought into contact with the living tissue without being inhibited by the contraction assisting unit 60.

  When the fluid is discharged from the inside of the balloon 30 through the expansion lumen 25 and the hub opening 41, the balloon 30 is deflated as shown in FIG. At this time, by providing the fixing portions 61 in the respective protruding portions 31 arranged in the circumferential direction, when the balloon 30 is deflated, the entire circumferential direction of the balloon 30 can be deflated substantially uniformly by the deflation assisting portion 60. it can. When the balloon 30 is deflated, it can be deflated small if the balloon 30 is in a folded state before expansion. However, it is usually difficult for the balloon 30 to return to the folded state before expansion, the shape is not stable, and it is difficult to shrink the balloon 30 small. In particular, when the length of the balloon 30 in the axial direction is long, the balloon 30 is deformed into a different shape depending on the position in the axial direction. Therefore, the shape is not stable, and it is difficult to contract it small. However, since the balloon catheter 10 according to the present embodiment is provided with the ring-shaped contraction assisting part 60 surrounding the outer peripheral surface of the balloon 30, when the fluid is discharged from the inside of the balloon 30, the contraction force of the contraction assisting part 60. Acts on the balloon 30 and the balloon 30 contracts small. Furthermore, since the plurality of shrinkage assisting portions 60 are provided in the axial direction of the outer peripheral surface of the balloon 30, even if the balloon 30 is long in the axial direction, the entire axial direction can be reliably contracted by the shrinkage assisting portion 60. . As a result, the used balloon 30 can be easily drawn into the sheath 70 (or guiding catheter) within the living body lumen and collected.

  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 catheter 10 described above is a rapid exchange type, but may be an over-the-wire type.

DESCRIPTION OF SYMBOLS 10 Balloon catheter 20 Shaft part 30 Balloon 31 Projection part 60 Contraction assistance part 61 Fixing part

Claims (4)

A long shaft,
A balloon which is provided by being folded on the outer peripheral surface of the distal portion of the shaft portion, and which is expandable when fluid flows into the interior;
And at least one ring-shaped contraction assisting part that surrounds a part of the outer peripheral surface of the folded balloon in the circumferential direction and has higher elasticity than the balloon,
At least a portion of the contraction assisting portion in the circumferential direction is slidable with respect to the balloon;
In a state where the balloon is expanded, the deflation assisting portion extends longer than a natural length and generates a deflation force.   The balloon catheter according to claim 1, wherein the contraction assisting part is fixed to a part of the outer peripheral surface of the balloon in the circumferential direction.   The balloon catheter according to claim 1 or 2, wherein a plurality of the contraction assisting portions are provided on the outer peripheral surface of the balloon along the axial direction.   The balloon catheter according to any one of claims 1 to 3, wherein the contraction assisting portion extends longer than a natural length in a state where the balloon is folded.

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