BALLOON-EQUIPPED TREATMENT TOOL FOR ENDOSCOPE, AND METHOD OF FOLDING BALLOON-EQUIPPED TREATMENT TOOL FOR ENDOSCOPE

According to one aspect, a balloon-equipped treatment tool for an endoscope includes a balloon, and a sheath connected to a proximal end side of the balloon and configured to introduce fluid to the balloon. The balloon includes a body portion having a first wall thickness, a cylindrical tail portion arranged on a proximal end side of the body portion and connected to the sheath, a cone portion located between the body portion and the tail portion, and a thick portion forming a second wall thickness larger than the first wall thickness. The thick portion whose distal end is arranged in the cone portion and whose proximal end is arranged in the tail portion.

BACKGROUND

Technical Field

The present invention relates to a balloon-equipped treatment tool for an endoscope, and a method of folding a balloon-equipped treatment tool for an endoscope.

Background Art

A technique for dilating a narrowed portion of a lumen such as a patient's digestive tract or blood vessel using a balloon-equipped treatment tool for endoscopy is known. This procedure is performed, for example, as follows. The operator first inserts the insertion portion of the endoscope into the patient's body so that the distal end of the endoscope comes to a position where the narrowed portion can be observed. The operator inserts the balloon-equipped treatment tool with the balloon folded into the treatment tool channel of the endoscope, and protrudes the balloon of the balloon-equipped treatment tool from the distal end of the treatment tool channel Next, while observing the balloon with an objective lens at the distal end of the endoscope, the operator inserts the balloon into the narrowed portion so that the balloon is positioned in the narrowed portion. The operator introduces fluid to the inside of the balloon through a sheath having a lumen inside that communicates with the balloon. As a result, the folding of the balloon is canceled and the balloon is expanded. The expansion of the balloon expands the narrowed portion around the balloon.

After that, the balloon is contracted by discharging the fluid existing inside the balloon through the lumen. Then, the balloon is removed from the dilated narrowed portion by pulling out the endoscopic balloon-equipped treatment tool from the treatment tool channel.

Such a procedure is performed while confirming the position and degree of expansion of the balloon in the image captured through the objective lens at the distal end of the endoscope.

For example, Japanese Patent Application, First Publication No. 2006-239156 Patent Document 1 describes a balloon-equipped treatment tool used for such a procedure.

SUMMARY

According to one aspect, a balloon-equipped treatment tool for an endoscope includes a balloon, and a sheath connected to a proximal end side of the balloon and configured to introduce fluid to the balloon. The balloon includes a body portion having a first wall thickness, a cylindrical tail portion arranged on a proximal end side of the body portion and connected to the sheath, a cone portion located between the body portion and the tail portion, and a thick portion forming a second wall thickness larger than the first wall thickness. The thick portion whose distal end is arranged in the cone portion and whose proximal end is arranged in the tail portion.

According to the balloon-equipped treatment tool for endoscopy in the above aspect, it is possible to suppress the occurrence of bump-shaped ridges in the balloon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are designated by the same reference numerals, and common description will be omitted.

First Embodiment

The balloon-equipped treatment tool for an endoscope according to a first embodiment of the present invention will be described.

FIG. 1is a schematic cross-sectional view showing an example of a balloon-equipped treatment tool for an endoscope according to the first embodiment of the present invention.FIG. 2is schematic side views showing how the balloon-equipped treatment tool according to the first embodiment of the present invention is folded.FIG. 3is a schematic front view showing a proximal end portion of an example of a balloon-equipped treatment tool according to the first embodiment of the present invention.FIG. 4is a view from an arrow A inFIG. 3.

As shown inFIG. 1, a balloon-equipped treatment tool10(balloon-equipped treatment tool for an endoscope) of the present embodiment is a long member extending from the proximal end on the right side of the drawing toward the distal end on the left side of the drawing. The balloon-equipped treatment tool10is inserted into the patient's lumen from the distal end through the treatment tool channel of an endoscope (not shown) inserted into the patient's lumen.

The balloon-equipped treatment tool10includes a sheath2, a reinforcing wire3, and a balloon1. As will be described later, the balloon1can be expanded from the contracted state and contracted from the expanded state.FIG. 1shows an expanded shape of the balloon1.

In the following, in the balloon-equipped treatment tool10and the members constituting the balloon-equipped treatment tool10, the direction along the axis is referred to as the axial direction, the direction around the axis is referred to as the circumferential direction, and the direction along the line intersecting the axis in the plane orthogonal to the axis is referred to as the radial direction. The axis can be defined with respect to an axial member or a cylindrical member, and corresponds to, for example, the central axis O of the balloon1and the central axis C of the sheath2.

The balloon1before being inserted into the treatment tool channel of the endoscope is folded into a plurality of thin blades in the contracted state. (a) inFIG. 2is a view of the balloon1in the expanded state, and (b) inFIG. 2is a view of the balloon1in the contracted state as viewed from the distal end side. A fluid is discharged from the inside of the balloon1in the expanded state shown in (a) inFIG. 2to make the balloon1transition to the contracted state. At this time, by pressing the balloon1from the periphery of the balloon1with a mold or the like (not shown), a plurality of blades BL are formed at different positions in the circumferential direction in the balloon1((b) inFIG. 2). In (b) inFIG. 2, three blades BL are formed, but the number of blades BL is not limited to three.

Each blade BL is formed by alternately applying mountain folds and valley folds to the balloon1in a direction parallel to the axis.

A mountain fold is formed by a folding method in which the inner surfaces of the balloon1are bent so as to face each other. At the distal end of each blade BL, a mountain fold portion f1made of a crease made by a mountain fold is formed.

A valley fold is formed by a folding method in which the outer surfaces of the balloon1are bent so as to face each other. A valley fold portion f2formed by a crease formed by a valley fold is formed between the blades BL adjacent to each other in the circumferential direction.

(c) inFIG. 2shows how each of the formed blades BL is further wound around the reinforcing wire3extending along the central axis of the balloon1. (d) inFIG. 2shows a state in which the winding of the blade BL is completed.

As shown in (d) inFIG. 2, in the contracted state, the balloon1is folded into a plurality of blades and wound around the central axis of the balloon1. As a result, the outer diameter of the balloon-equipped treatment tool10can be made as small as possible, and the balloon1is devised so that the channel for the treatment tool of the endoscope can be smoothly inserted.

The type of lumen into which the balloon-equipped treatment tool10is inserted is not limited. For example, the balloon-equipped treatment tool10may be inserted into the gastrointestinal tract such as the esophagus, pylorus, bile duct, and large intestine. The outer diameter of the balloon-equipped treatment tool10when the balloon1is contracted and the maximum outer diameter when the balloon1is expanded are preset according to the inner diameter of the lumen to be inserted and the channel for the treatment tool.

The sheath2is a long member that introduces the fluid F that expands the balloon1to the balloon1. The fluid F may be a liquid or a gas.

The sheath2may be formed by a single tube or may be formed by a plurality of tubes. The sheath2may be a single-layer tube or a multi-layer tube.

Examples of the material of the sheath2include nylon, polyamide, PTFE (polytetrafluoroethylene), PE (polyethylene), PP (polypropylene) and the like.

Inside the sheath2, a lumen2cthat penetrates from the proximal end2ato the distal end2bof the sheath2is formed. A reinforcing wire3is inserted in the lumen2c.

The inner diameter of the lumen2cis larger than the outer diameter of the reinforcing wire3described later. Therefore, the fluid F can flow through the lumen2cwith the reinforcing wire3inserted therein.

A base5connected to a fluid-introducing device (not shown) is connected to the proximal end2aof the sheath2. The lumen2cat the proximal end2acommunicates with the opening5aof the base5.

The distal end2bis formed with a distal end opening2dthat communicates with the lumen2c.

The reinforcing wire3supports the balloon1, which will be described later, substantially coaxially with the sheath2. The reinforcing wire3has flexibility such that it can be bent depending on the magnitude of the external force acting through the lumen into which the balloon-equipped treatment tool10is inserted or the treatment tool channel Therefore, the reinforcing wire3can be curved along the lumen or the treatment tool channel.

The length of the reinforcing wire3is substantially equal to the sum of the lengths of the sheath2and the balloon1.

The proximal end3aof the reinforcing wire3is fixed to the base5. The reinforcing wire3protrudes from the distal end opening2dof the sheath2and extends in front of the distal end2b. The distal end3bof the reinforcing wire3is fixed to the distal end convex portion4.

For example, as the material of the reinforcing wire3, nickel-titanium alloy, stainless steel, or the like is used.

The distal end convex portion4is a rod-shaped member having an outer diameter substantially equal to the outer diameter of the sheath2except for the distal end portion. The distal end portion of the distal end convex portion4has a tapered shape and is rounded so that the diameter gradually decreases toward the distal end side.

The balloon1is softer than the sheath2and is made of a stretchable resin film. The shape of the balloon1is a cylinder centered on the central axis O in the expanded state.

Inside the balloon1, the proximal end portion of the distal end convex portion4, the reinforcing wire3, and the distal end portion of the sheath2are inserted.

As will be described later, the proximal end portion of the balloon1is firmly fixed to the distal end portion of the sheath2, and the distal end portion of the balloon1is closely fixed to the proximal end portion of the distal end convex portion4. As a result, an internal space I communicating with the lumen2cof the sheath2is formed inside the balloon1. The fluid F introduced to the internal space I is held inside the balloon1.

As shown inFIG. 1, the balloon1has a first tail portion1A (tail portion), a first cone portion1B (cone portion), a body portion1C, a second cone portion1D, and a second tail portion1E from the proximal end side to the distal end side.

When the reinforcing wire3extends straight, the balloon1is arranged coaxially with the central axis C of the sheath2.

As shown inFIG. 3, the first tail portion1A of the balloon1is a cylindrical portion, and has a distal end portion1Ad on the distal end side and a proximal end portion1Ap on the proximal end side. The inner peripheral surface of the proximal end portion1Ap is fixed in close contact with the outer peripheral surface of the distal end portion of the sheath2. The wall thickness of the first tail portion1A is constant except for variations due to manufacturing errors.

The method of fixing the first tail portion1A to the sheath2is not particularly limited as long as the fluid F can be sealed inside. For example, the first tail portion1A may be fixed to the outer peripheral surface of the sheath2by heat fusion or the like. Since the proximal end portion1Ap is integrated with the sheath2, it is equivalent to the sheath2in terms of flexibility and expandability. For example, the inner diameter and outer diameter of the proximal end portion1Ap do not change even if the pressure of the fluid F changes.

On the other hand, in the first tail portion1A, the distal end portion1Ad closer to the distal end than the proximal end portion1Ap is not fixed to the sheath2.

Therefore, the distal end portion1Ad has flexibility and expandability according to its rigidity.

The first cone portion1B is a hollow portion whose diameter gradually increases from the distal end of the first tail portion1A toward the body portion1C described later. The first cone portion1B is arranged coaxially with the central axis C of the sheath2when the reinforcing wire3(not shown) extends straight.

The rate of change in the diameter of the first cone portion1B may be constant or may be changed. For example, the shape of the first cone portion1B may be a conical surface, or may be various shapes curved outward or inward from the conical surface by changing the rate of change in diameter. For example, the shape of the first cone portion1B may be a bowl type, a cannonball type, a bell type, a funnel type, a horn type, or the like.

For example, in the example shown inFIG. 3, the expansion ratio of the outer diameter of the first cone portion1B gradually increases from the point P1at the boundary with the first tail portion1A, becomes maximum at the point P2, and gradually decreases from the point P2toward the point P3at the boundary with the body portion1C. Taking a cross section including the point P2and the central axis C, the point P2is an inflection point of the inclination curve of the first cone portion1B.

The wall thickness of the first cone portion1B may change depending on the position in the axial direction, but if the positions in the axial direction are the same, the wall thickness in the circumferential direction is constant except for variations due to manufacturing errors.

The body portion1C has a constant outer diameter from the distal end of the first cone portion1B, and is a cylindrical portion centered on the central axis O. The body portion1C is preferably smoothly connected to the distal end of the first cone portion1B.

The wall thickness of the body portion1C is substantially equal to the wall thickness of the distal end of the first cone portion1B.

The length of the body portion1C is set to an appropriate length according to the length of the narrowed portion.

The second cone portion1D is a hollow portion whose diameter is gradually reduced from the distal end of the body portion1C toward the second tail portion1E described later. The second cone portion1D may have the same configuration as the first cone portion1B except that the thick portion1ais not formed.

The second tail portion1E is a cylindrical portion centered on the central axis O extending from the distal end of the second cone portion1D. The proximal end portion of the second tail portion1E is closely fixed to the outer peripheral surface of the distal end convex portion4. The second tail portion1E may have the same configuration as the first tail portion1A except that the thick portion1ais not formed.

The method of fixing the second tail portion1E to the distal end convex portion4may be the same as the method of fixing the first tail portion1A to the sheath2.

Such a balloon1is formed of a resin material that can elastically expand and contract by the pressure of the fluid F. The material of the balloon1is preferably sufficiently translucent. It is more preferable that the transmittance of the material of the balloon1be close to 100%.

As the material of the balloon1, it is more preferable that the shore hardness be large for the purpose of enabling expansion at a high-pressure resistance. For example, it is more preferable that a material having a shore hardness of D40 or higher be used for the shore hardness of the material of the balloon1.

The balloon1may be formed of, for example, one or more resin materials selected from the group consisting of a polyamide elastomer and a polyamide resin.

When the balloon1is formed of a plurality of materials, different materials may be used depending on the site of the balloon1. One part selected from the first tail portion1A, the first cone portion1B, the body portion1C, the second cone portion1D, the second tail portion1E, and the thick portion1amay be made of a material different from any other part.

When the balloon1is formed of a plurality of materials, for example, the plurality of materials may be laminated in the radial direction.

In the first tail portion1A and the first cone portion1B, a ridge-shaped thick portion1aextending on the first tail portion1A and the first cone portion1B is formed. The thick portion1ais a portion where the resin forming the balloon1rises like a mountain range, and is formed from the first tail portion1A to the first cone portion1B. The wall thickness of the first tail portion1A or the first cone portion1B in which the thick portion1ais formed is thicker than the wall thickness of the first tail portion1A or the first cone portion1B in which the thick portion1ais not formed by the amount of the ridge of the thick portion1a.

The number of thick portions1ais not particularly limited as long as the occurrence of bump-shaped ridges, which will be described later, can be suppressed. Considering that the balloon1is bent in various directions at the proximal end portion1Ap, the number of the thick portions1ais preferably a plurality, more preferably three or more. In the example shown inFIGS. 3 and 4, the number of thick portions1ais 3. As shown inFIG. 3, each thick portion1aextends from the distal end portion1Ad to the first cone portion1B in a ridge pattern.

It is preferable that the position of the distal end of the thick portion1abe within the first cone portion1B (unless it has advanced to the body portion1C), because the state in which the blade BL of the balloon1is wound is realized with a small diameter as shown in (d) inFIG. 2. For example, the thick portion1amay extend to the center of or near the center of the first cone portion1B in the axial direction. For example, when the inclination curve of the first cone portion1B has an inflection point, the thick portion1amay extend to the inflection point or its vicinity. Here, the “neighborhood” is defined as a range of ±δ of the position of the center or the inflection point in the axial direction, where δ is 20% of the length of the first cone portion1B in the axial direction.

It is preferable that the thick portion1aextend to or near the inflection point, because the thick portion1ahardly hinders the observation of the narrowed portion through the balloon1and a sufficient reinforcing effect can be obtained to suppress the occurrence of bump-shaped ridges.

In order to give uniform directionality to the bending at the proximal end portion1Ap of the balloon1, when there are a plurality of thick portions1a, it is more preferable that the distance from the center of the first cone portion1B to the distal end of each thick portion1abe equal to or substantially equal to each other. Here, substantially equal is defined as the difference in the length of each thick portion1awith respect to the average length of each thick portion1awithin the range of ±20% of the average length.

The detailed shape of the ridges in each thick portion1ais not particularly limited. For example, the width of each thick portion1amay be constant or may vary. Here, the width of the thick portion1ais defined as a dimension perpendicular to the extending direction of the thick portion1aand along the surface of the balloon1. The wall thickness of the thick portion1ais defined as a dimension perpendicular to the extending direction of the thick portion1aand in the wall thickness direction of the balloon1. When the width changes, it is more preferable to reduce the width monotonously in a broad sense from the proximal end to the distal end of the thick portion1a. Here, narrowing to a monospaced font in a broad sense means that a monospaced change may be included in a part thereof.

In the example shown inFIG. 4, each thick portion1ais narrowed monotonously in a narrow sense from the proximal end to the distal end. Here, narrowing monospaced in a narrow sense means not including a monospaced change.

In the thick portion1a, it is more preferable that the width in the first tail portion1A be wider than the width in the first cone portion1B, but variations in the width change are possible.

FIG. 5shows the thick portions1a1,1a2, and1a3as examples of variations in the width of the thick portion1a.

In the example of the thick portion1a1shown inFIG. 5A, the width of the ridge-shaped thick portion1a1is narrowed from the proximal end T1atoward the distal end T1b. In the case of such a shape, since the area occupied by the thick portion1a1in the first cone portion1B of the balloon1is smaller than the area occupied by the first tail portion1A, it is narrowed through the first cone portion1B of the balloon1. When observing the portion with an endoscope, the degree to which the thick portion1a1interferes with the observation is low. Further, the presence of the thick portion1a1at the time of contraction of the balloon1hinders the formation of the blades to a low degree.

In the example of the thick portion1a2shown inFIG. 5B, the width of the ridge-shaped thick portion1a2is narrow at the proximal end T2aand the distal end T2b, and slightly wide at the intermediate portion M2. According to this shape, since the shape of the thick portion1a2becomes slender as a whole, there is an advantage in that the diameter of the blade BL after winding can be reduced as shown in (d) inFIG. 2.

In the example of the thick portion1a3shown in (c) inFIG. 5, the width of the ridge-shaped thick portion1a3widens from the proximal end T3atoward the distal end T3b. In the case of such a shape, the first cone portion1B is less deformed when the proximal end portion of the balloon1is bent due to an angle operation. As a result, the occurrence of wrinkles and bump-shaped ridges is more effectively suppressed.

However, the variation of the change in the width of the thick portion1ais not limited to the above example.

The extending direction of the thick portion1ais not particularly limited as long as it is in the direction from the distal end portion1Ad to the first cone portion1B.

It is more preferable that the direction of the ridges of the thick portion1a(extending direction) be along the longitudinal direction of the balloon1(direction along the central axis O). That is, it is more preferable that the thick portion1aextend in the longitudinal direction of the balloon1when viewed from an appropriate radial direction. In other words, the center line extending in the extending direction of the thick portion1ais included in an appropriate plane including the central axis O, and the thick portion1aextends from the proximal end side of the balloon1toward the distal end side along the surfaces of the first tail portion1A and the first cone portion1B.

For example, in the example shown inFIG. 4, each thick portion1aextends radially from the center of the first cone portion1B when viewed from the axial direction. Further, each thick portion1aextends in the radial direction so as to divide the circumference concentric with the first cone portion1B into three equal parts. It is preferable that the direction in which each thick portion1aviewed from the axial direction extends be radial, which divides the circumference into three or more equal parts, because it can evenly respond to bending of the distal end of the endoscope in various directions due to the angle operation.

When the thick portion1aextends radially from the center of the first cone portion1B, each thick portion1aextends in the longitudinal direction of the balloon1(direction along the central axis O) when viewed from an appropriate radial direction.

It is preferable that each thick portion1aextend radially from the center of the first cone portion1B when viewed from the axial direction, as it is effective in suppressing the generation of bumps. However, when viewed from the axial direction, the stretching direction of the thick portion1amay be inclined with respect to the radial direction. Further, the thick portion1amay extend in a curved ridge shape.

In the example shown inFIG. 3, when viewed from an appropriate radial direction, each thick portion1aextends in the longitudinal direction of the balloon1, so the size of the width of the thick portion1acan be measured in a cross section orthogonal to the central axis O (hereinafter, referred to as a cross section perpendicular to the axis). The width of the thick portion1amay be constant or variable in the extending direction.

FIGS. 6A, 6B, and 6Cshow the type of shape of the thick portion1ain the cross section perpendicular to the axis in the first cone portion1B. InFIGS. 6A, 6B, and 6C, the width of the thick portion1ais represented by w.FIGS. 6D, 6E, and 6Fshow the type of shape of the thick portion1ain the cross section perpendicular to the axis in the first tail portion1A. InFIGS. 6D, 6E, and 6F, the width of the thick portion1ais represented by w′.

Regarding a width w in the first cone portion1B and a width w′ in the first tail portion1A of the thick portion1a, as shown inFIG. 5A, when the width of the thick portion1ais narrowed from the proximal end to the distal end, w<w′. As shown inFIG. 5B, when the width of the thick portion1ais narrow at the proximal end and the distal end and wide at the middle, w≈w′. As shown inFIG. 5C, when the width of the thick portion1ais widened from the proximal end to the distal end, w>w′.

A wall thickness t1in the first cone portion1B of the thick portion1aand a wall thickness t1′ in the first tail portion1A are determined according to the shape of the thick portion1a.

Regarding a wall thickness t0of the first cone portion1B and a wall thickness t0′ of the first tail portion1A other than the thick portion1a, since the first cone portion1B is stretched and thinned when the balloon1is formed, usually t0<t0′.

For example, as schematically shown inFIGS. 6A and 6D, the thick portion1amay be a ridge protruding radially outward from the outer peripheral surface So of the first tail portion1A and the first cone portion1B (hereinafter referred to as an outward protruding type). InFIGS. 6A and 6D, the protruding shape of the thick portion1ais drawn in a semicircular shape, but the protruding shape is not limited to this. For example, the protruding shape may be an ellipse, a bell, a triangle, a rectangle, a trapezoid, a polygon, or the like. For example, in each cross-sectional shape, the boundary portion with the outer peripheral surface So may be formed by a smooth curve. Hereinafter, the cross-sectional shapes ofFIGS. 6B, 6C, 6E, and 6Fare the same.

In the case of the outward protruding type shown inFIGS. 6A and 6D, the shape of the cross section perpendicular to the axis of the inner peripheral surface Si of the first tail portion1A or the first cone portion1B is circular. The wall thickness t1or t1′ of the thick portion1ais the distance from the inner peripheral surface Si to the top of the muscle. The wall thickness t1or t1′ may be constant or variable in the extending direction. It is preferable that the wall thickness t1or t1′ of the thick portion1abecome monotonously thin in a broad sense from the first tail portion to the first cone portion. In this case, it is suitable because it sufficiently reinforces the vicinity of the boundary between the first tail portion1A and the first cone portion1B where stress tends to be concentrated due to bending, and does not hinder the visibility of the narrowed portion of the balloon. The wall thickness t1or t1′ of the thick portion1ais a value obtained by adding the amount of protrusion from the outer peripheral surface So of the muscle to the wall thickness t0of the first tail portion1A or the first cone portion1B or the wall thickness t0′ of the first tail portion.

For example, as shown inFIGS. 6B and 6E, the thick portion1amay be a ridge having a width w protruding radially inward from the inner peripheral surface Si (hereinafter referred to as an inward protruding type). In the case of the inwardly protruding type, the shape of the cross section perpendicular to the axis of the outer peripheral surface So is circular. The wall thickness t1or t1′ of the thick portion1ais equal to the distance from the outer peripheral surface So to the top of the muscle. The wall thickness t1of the thick portion1ais a value obtained by adding the wall thickness t0of the first cone portion1B or the wall thickness t0′ of the first tail portion1A to the amount of protrusion from the inner peripheral surface Si of the muscle.

As shown inFIGS. 6C and 6F, the thick portion1amay be a ridge protruding radially outward and inward from the outer peripheral surface So and the inner peripheral surface Si (hereinafter, referred to as an inner/outer protruding type). Here, when the width of the ridges differs between the outer peripheral surface So and the inner peripheral surface Si, the wider width is used to represent the width of the ridges.

The wall thickness t1of the thick portion1ais equal to the radial distance of the apex of each ridge on the outer peripheral surface So and the inner peripheral surface Si. The wall thickness t1or t1′ of the thick portion1ais a value obtained by adding each protrusion amount from the outer peripheral surface So and the inner peripheral surface Si of the muscle to the wall thickness t0of the first cone portion1B or the wall thickness t1′ of the first tail portion1A. In the case of the inner/outer protrusion type, the amount of protrusion of each muscle on the outer peripheral surface So and the inner peripheral surface Si may be the same or different from each other.

FIGS. 6A, 6B, 6C, 6D, 6E, and 6Fshow an example in which the cross-sectional shapes of the thick portions1aare similar to each other. However, the cross-sectional types of the thick portions1amay be different from each other. For example, in the cross section perpendicular to the axis, two or more of the inward projecting type, the outward projecting type, and the inward/outward projecting type may be mixed as the type of cross-sectional shape of the plurality of thick portions1a.

The type of cross-sectional shape of each thick portion1amay be constant in the axial direction or may differ depending on the position of the cross-sectional section perpendicular to the axis.

For example, the wall thickness t0′ of the first tail portion1A may be 180 μm or more and 250 μm or less. The wall thickness t0′ of the first tail portion1A is more preferably 180 μm or more and 210 μm or less. Within the above wall thickness range, the balloon1can be securely fixed to the sheath2, and the diameter of the balloon1when folded is sufficiently small so that it does not interfere with the insertion of the endoscopic treatment tool insertion channel.

For example, the wall thickness t0of the first cone portion1B may be 35 μm or more and 120 μm or less. The wall thickness t0of the first cone portion1B is more preferably 40 μm or more and 60 μm or less. Within the above wall thickness range, sufficient translucency can be ensured for observing the narrowed portion through the balloon1using the objective lens at the distal end of the endoscope while sufficiently maintaining the wall strength of the first cone portion1B.

As will be described later, the thick portion1ais provided for the purpose of suppressing bump-shaped ridges caused by wrinkles generated in the first tail portion1A and the first cone portion1B in the expanded state of the balloon1. Therefore, it is preferable that the thick portion1ahave a wall thickness and a width that can remain at least in the expanded state, rather than being stretched and disappearing by the expansion of the balloon1. Even when the balloon1is expanded at various expansion rates, it is more preferable that the wall thickness and width of the thick portion1aremain at all expansion rates.

For example, from the viewpoint that the effect of suppressing the occurrence of bump-shaped ridges is sufficient, and the diameter of balloon1does not increase when folded, the wall thickness t1or t1′ of the thick portion1amay be 180 μm or more and 250 μm or less. The wall thickness t1or t1′ of the thick portion1ais more preferably 180 μm or more and 200 μm or less.

From the same viewpoint, the width w or w′ of the thick portion1amay be 1.0 mm or more and 2.0 mm or less. The width w or w′ of the thick portion1ais more preferably 1.0 mm or more and 1.6 mm or less.

The balloon1may be manufactured, for example, by blow molding using a molding mold that transfers the shape of the expanded state.

For example, a parison tube made of the same material as the balloon1is manufactured. As the parison tube, for example, a cylindrical tube is used.

Blow molding is performed by arranging this parison tube inside the above-mentioned molding mold. That is, the parison tube expands toward the inner surface of the molding die, adheres to the molding surface of the molding die, and hardens, so that the shape of the molding surface is transferred to the outer surface of the expanded parison tube. Thereby, the balloon1is manufactured.

At that time, the thick portion1ais formed by appropriately setting the shape of the molding die or the molding conditions for blow molding. In order to form the outwardly protruding thick portion1aas shown inFIGS. 6A and 6D, for example, a groove portion for transferring the protruding shape of the thick portion1amay be formed in the molding die. In order to form the inwardly protruding thick portion1aas shown inFIGS. 6B and 6E, for example, the molding conditions are adjusted so that wall thickness unevenness in the circumferential direction occurs when the parison tube is expanded. Similarly, the forming conditions may be adjusted to form the outwardly projecting thick portion1a. In this case, the thick portion1aprotrudes inward at the time of molding, but when the fluid F flows into the balloon1after demolding, the thick portion1aprotrudes outward due to the pressure of the fluid F.

In order to form the inner/outer protruding type thick portion1aas shown inFIGS. 6C and 6F, the manufacturing methods of the outward protruding type and the inward protruding type thick portion1amay be combined.

After that, the assembly of the distal end convex portion4, the reinforcing wire3, and the sheath2is inserted into the central portion of the balloon1. The first tail portion1A and the second tail portion1E, respectively, are fixed on the outer peripheral surfaces of the distal end portion and the distal end convex portion4of the sheath2.

As shown in (b), (c), and (d) inFIG. 2, the balloon1fixed to the distal end convex portion4and the sheath2is folded so as to have creases such as a mountain fold portion f1and a valley fold portion f2by a well-known folding process or the like, and is wound around the reinforcing wire3in the balloon1. In this way, the balloon-equipped treatment tool10is manufactured.

In the balloon1, the first tail portion1A and the second tail portion1E are fixed in close contact with the outer peripheral surfaces of the distal end portion and the distal end convex portion4of the sheath2, respectively. Inside the balloon1, an internal space I through which the fluid F can enter and exit is formed between the proximal end2aand the distal end convex portion4through the distal end opening2d.

The balloon1is expanded when the fluid F flows into the internal space I. When the pressure of the fluid F increases, the balloon1expands, so that an expanded state corresponding to the pressure received by the balloon1can be obtained.

Next, the action of the balloon-equipped treatment tool10will be described focusing on the action of the thick portion1a.

First, the balloon1at the distal end of the balloon-equipped treatment tool10is inserted into the narrowed portion of the patient in a reduced state by a well-known procedure using an endoscope. Specifically, the balloon-equipped treatment tool10is inserted into the treatment tool channel of the endoscope with the balloon1as the distal end. The distal end of the endoscope is located near the narrowed portion. The surgeon looks at the image in front of the distal end of the endoscope and adjusts the position and posture of the distal end of the endoscope so that the opening of the treatment tool channel faces the narrowed portion. After this, the operator inserts the balloon1into the narrowed portion by feeding out the balloon-equipped treatment tool10from the opening of the treatment tool channel. At this time, the feeding direction of the balloon1is a direction parallel to the central axis of the channel for the treatment tool, and the central axis O of the balloon1and the central axis C of the sheath2are coaxial.

After that, the operator operates the fluid-introducing device connected to the base5of the balloon-equipped treatment tool10to introduce the fluid F to the inside of the balloon1through the sheath2. As a result, the balloon1inserted into the narrowed portion is expanded. The expansion rate of the balloon1is selected by the operator according to the narrowed portion.

FIG. 7is an operation explanatory view of the balloon-equipped treatment tool for an endoscope according to the first embodiment of the present invention. For example,FIG. 7Aschematically shows how the narrowed portion N is expanded by the balloon1. The facing distances of the narrowed surfaces Na and Nb facing each other on the inner surface of the narrowed portion N are expanded to a distance equal to the outer diameter of the expanded body portion1C as compared with before the balloon1was expanded.

In the endoscope50used for inserting the balloon-equipped treatment tool10, the distal end portion51is fixed to the distal end of the curved portion55. The operator can change the bending amount and bending direction of the bending portion55by operating the operation portion (not shown) of the endoscope50. As a result, the operator can perform an angle operation for changing the direction of the distal end portion51provided at the distal end of the curved portion55.

An opening52aof the treatment tool channel52is opened at the distal end of the distal end portion51. Further, an imaging unit53and an illumination unit54are arranged at the distal end of the distal end portion51.

The imaging unit53includes an imaging lens that captures an image in front of the distal end portion51, an imaging element that photoelectrically converts an optical image formed by the imaging lens, and the like. The image signal photoelectrically converted by the imaging element is transmitted to the proximal end side of the endoscope50, and an image corresponding to the image signal is displayed on a monitor (not shown).

The illumination unit54emits illumination light that illuminates the visual field range of the imaging unit53.

The optical axes of the imaging unit53and the illumination unit54and the central axis of the treatment tool channel52are all parallel to the central axis of the distal end portion51.

For example, as shown inFIG. 7A, in a state where the balloon1is expanded immediately after the balloon1is inserted into the narrowed portion N, the distal end portion51faces the entrance of the narrowed portion N. In this case, since the optical axes of the imaging unit53and the illumination unit54are substantially parallel to the central axis O of the balloon1, the imaging range of the imaging unit53is substantially centered on the center axis O. In order to take a precise image with a high-resolution image, when the narrowed portion is directly imaged without using the light transmitted through the balloon1, the contact portion between the balloon1and the narrowed surfaces Na and Nb does not fall within the imaging range, or even if it does, it is a peripheral portion of the imaging range. Therefore, even if the operator looks at the image on the monitor, the operator may not be able to see whether or not the narrowed portion N is properly expanded, or it may be difficult to see. Further, even when observing the narrowed portion with the light transmitted through the balloon1, if the sheath2or the like greatly enters the observation range, it becomes an obstacle.

The surgeon moves the imaging range for the purpose of making it easier to see the expanded state of the narrowed portion N. Specifically, the surgeon changes the direction of each optical axis of the imaging unit53and the illumination unit54by performing an angle operation while looking at the image on the monitor.

For example, (b) inFIG. 7shows a state in which the distal end portion51is tilted for the purpose of observing the expanded state in the narrowed surface Na. Since the balloon1is restrained by the narrowed portion N, the posture of the balloon1does not change as a whole.

Therefore, the central axis of the distal end portion51is inclined with respect to the central axis O. Since the treatment tool channel52is also inclined with respect to the central axis O, the sheath2in the treatment tool channel52is inclined with respect to the central axis O like the treatment tool channel52.

As a result, the balloon1is bent in the region of the first tail portion1A and the first cone portion1B, which are softer than the sheath2. For example, the central axis C of the sheath2is inclined by θ with respect to the central axis O.

For the purpose of observing the expanded state of the narrowed surface Nb, for example, the operator may incline the distal end portion51in the direction opposite to that in (b) inFIG. 7. In this case, although not particularly shown, for example, the central axis C of the sheath2may be inclined by about θ in the direction opposite to the central axis O.

As described above, in the procedure for expanding the narrowed portion N by the balloon1, the first tail portion1A and the first cone portion1B are bent in various directions for the purpose of observing the expanded state of the narrowed portion N by the balloon1.

As the material of the balloon1, a material having a large shore hardness is often selected for the purpose of achieving high withstand voltage. A material having a large shore hardness has high durability during expansion, but for example, deformation marks such as wrinkles are likely to remain during bending. This tendency is particularly remarkable when the shore hardness is D40 or more. Therefore, even if the balloon1is formed of a material having a large shore hardness, there is a strong demand for a technique in which deformation marks are less likely to remain.

FIG. 8is a schematic diagram illustrating the operation of the balloon-equipped treatment tool for an endoscope and the comparative example according to the first embodiment of the present invention. InFIG. 8, (b1), (b2), (b3), and (b4) show an example of a balloon100as a comparative example.

The balloon100of the comparative example has the same configuration as the balloon1except that it does not have the thick portion1a. The balloon100is fixed to the distal end convex portion4(not shown) and the sheath2in the same manner as the balloon1.

When the angle operation of the endoscope50(not shown) is performed from the state where the central axes O and C are coaxial (see (b1) inFIG. 8), the first tail portion1A or the first cone portion1B in the vicinity of the first tail portion1A is bent (see (b2) inFIG. 8). At this time, wrinkles k are generated on the balloon100inside the bending at the bending portion. If the material is plastically deformed when wrinkles are generated, traces of wrinkles remain. Therefore, even if the central axes O and C are returned to the coaxial state, the wrinkles k remain as deformation marks to some extent.

When the operator observes the expanded state of the narrowed portion N over the entire circumference, it is necessary to operate the angle in various directions. When the angle operation is performed in the other direction, wrinkles k are generated inside the bending of the new bending portion. The new wrinkle k may intersect the existing wrinkle k that has already been formed. In this case, the existing wrinkles k are bent to form more complicated wrinkles, so that the balloon100is hardened.

When the angle operation in the same direction or substantially the same direction is repeated, the same wrinkle k is repeatedly formed, which causes a crease, and the wrinkle k may gradually increase.

When the operator finishes observing the dilated state of the narrowed portion N, as shown in (b3) inFIG. 8, a large number of wrinkles k are formed on the distal end side of the first tail portion1A and the proximal end side of the first cone portion1B. The wrinkles k are raised like bumps on the outside of the balloon100.

The balloon100is reduced by discharging the fluid F when the expansion of the narrowed portion N is completed (see (b4) inFIG. 8). At this time, if the wrinkles k raised in a bump shape are formed, the outer diameter of the balloon100in the reduced state becomes larger than the outer diameter of the first tail portion1A. If the amount of wrinkle k ridge is too large, it may be difficult for the reduced balloon100to be pulled out through the treatment tool channel52.

On the other hand, inFIG. 8, (a1), (a2), (a3), and (a4) show an example of the balloon1of the present embodiment.

According to the balloon1of the present embodiment, a ridge-shaped thick portion1ais formed extending on the first tail portion1A and the first cone portion1B (see (a1) inFIG. 8).

Since the thick portion1ais thicker than the first tail portion1A and the first cone portion1B, it is unlikely to be plastically deformed even if it is bent. Further, since the thick portion1ais ridge-shaped, elastic bending deformation is easier than in the case where the first tail portion1A or the first cone portion1B is uniformly thickened.

As a result, as shown in (a2) inFIG. 8, it is possible to suppress the occurrence of wrinkles that form bump-shaped ridges without impairing the flexibility of the balloon1in the angle operation.

Therefore, as shown in FIG.8A4, the outer diameter of the balloon1in the reduced state does not become significantly larger than the outer diameter of the first tail portion1A. As a result, the balloon1in the reduced state can be easily pulled out through the treatment tool channel52.

When the balloon1is made of a translucent material and the operator observes the narrowed surface Na in contact with the balloon1through the balloon1, the thick portion1aalso has translucency, but the image that has passed through the thick portion1amay be distorted. In order to facilitate observation through the balloon1, it is more preferable that the thick portions1aadjacent to each other in the circumferential direction have a wide distance. Therefore, as long as there is no problem in suppressing the generation of bumps, it is more preferable that the width of the thick portion1abe narrow as long as the number of the thick portions1ais the same. If the widths of the thick portions1aare the same, it is more preferable that the number of the thick portions1abe small.

Since the balloon1abuts on the narrowed portion N at the body portion1C, in order to make it easier to observe the contact state with the narrowed portion N, it is more preferable that the thick portion1anot extend to the first cone portion1B near the body portion1C. For example, if the distal end of the thick portion1aextends to the center of the first cone portion1B in the axial direction and its vicinity thereof, it is more preferable in that observation through the first cone portion1B closer to the body portion1C becomes easier.

When the thick portion1aextends radially from the center of the first cone portion1B, since the distance between the thick portions1aadjacent to each other in the circumferential direction becomes wider toward the distal end side, it becomes easier to observe the contact state with the narrowed portion N. Similarly, even when the width of the thick portion1ais narrower in the first cone portion1B than in the first tail portion1A, since the distance between the thick portions1aadjacent to each other in the circumferential direction becomes wider toward the distal end side, it becomes easier to observe the contact state with the narrowed portion N.

As described above, according to the balloon-equipped treatment tool10of the present embodiment, it is possible to suppress the occurrence of bump-shaped ridges in the balloon1.

First to Fourth Modified Examples

Next, the balloon-equipped treatment tool for an endoscope of the modified example (first to fourth modified examples) of the first embodiment will be described.

FIG. 9is a schematic side view showing the balloon in the balloon-equipped treatment tool for an endoscope according to the first embodiment of the present invention (first to fourth modified examples).

As shown inFIG. 1, the balloon-equipped treatment tool10A (balloon-equipped treatment tool for an endoscope) of the first modification includes a balloon11instead of the balloon1in the first embodiment. Hereinafter, the features different from the first embodiment will be mainly described.

As shown in (a) inFIG. 9, the balloon11of this modification is different from the balloon1in that it has four thick portions1asimilar to those of the first embodiment. Each thick portion1ain the balloon11extends radially from the center of the first cone portion1B. In the example shown in (a) inFIG. 9, each thick portion1aextends in the radial direction that divides the circumference concentric with the first cone portion1B into four equal parts. The direction in which each thick portion1aviewed from the axial direction extends may be radial without evenly dividing the circumference.

As shown inFIG. 1, the balloon-equipped treatment tools10B,10C, and10D (balloon-equipped treatment tools for endoscopy) of the second modification, the third modification, and the fourth modification include balloons12,13,14instead of the balloon1in the first embodiment. Hereinafter, the features different from the first embodiment will be mainly described.

As shown in (b), (c) and (d) inFIG. 9, the balloons12,13, and14are different from the balloon1in that they have the same thick portions1aas those in the first embodiment, the number of which is 5, 6, and 8, respectively. Each thick portion1ain the balloons12,13and14extends radially from the center of the first cone portion1B. In the example shown in (b), (c) and (d) inFIG. 9, each thick portion1aextends in the radial direction in which the circumference concentric with the first cone portion1B is divided into five equal parts, six equal parts, and eight equal parts. However, the direction in which each thick portion1aviewed from the axial direction extends may be radial without evenly dividing the circumference.

The balloon-equipped treatment tools10A,10B,10C, and10D of the first to fourth modifications are configured in the same way as the balloon-equipped treatment tools10of the first embodiment, except that the number of thick portions1ain the balloons11,12,13, and14is different. Therefore, the balloon-equipped treatment tools10A,10B,10C, and10D can suppress the occurrence of bump-shaped ridges in the balloons11,12,13, and14, similar to the balloon-equipped treatment tool10.

Fifth Modification

Next, the balloon-equipped treatment tool for an endoscope of the fifth modification of the first embodiment will be described.

As shown inFIG. 1, the balloon-equipped treatment tool10F (balloon-equipped treatment tool for an endoscope) of this modified example includes a balloon16instead of the balloon1of the first embodiment. Hereinafter, the features different from the first embodiment will be mainly described.

FIGS. 10A, 10B, 10C, and 10Dare schematic perspective views showing a balloon used as a balloon-equipped treatment tool for an endoscope according to a fifth modification of the first embodiment of the present invention.

In the balloon16, the thick portion1ais arranged so as to be connected to the mountain fold portion f1of the balloon fold in relation to the blade BL of the balloon1shown inFIG. 2.FIG. 10Acorresponds to (a) inFIG. 5,FIG. 10Bcorresponds to (b) inFIG. 5, andFIG. 10Ccorresponds to (c) inFIG. 5. In each balloon16, the mountain fold line f1at the time of folding the balloon16is located on the extension of each of the ridge-shaped thick portions1a1,1a2,1a3. That is, the virtual line in which the ridges of the thick portions1a1,1a2,1a3are extended along the surface of the balloon16overlaps with the mountain fold line f1. With this configuration, when the balloon16is folded, the ridges of the thick portions1a1,1a2,1a3are aligned with the mountain fold line f1of the blade BL (not shown), so the presence of the thick portions1a1,1a2,1a3does not interfere with the folding of the blade BL. As a result, the blade BL can be neatly folded and the diameter can be reduced.

The distal ends T1b, T2b, and T3bof each thick portion1a1,1a2,1a3may extend to the end of the mountain fold portion f1, respectively.

For example, as shown inFIG. 10D, the distal end T4bof the thick portion1a4may be located at the body portion1C which is the cylindrical portion of the balloon16, and the distal end T4bmay reach the end of the mountain fold portion f1. In this case, the folding work is guided by each thick portion1a4, which is preferable.

Further, although not particularly shown, even if the thick portion1ais not connected to the folded mountain fold portion f1and the positions of the two are slightly displaced in the circumferential direction, when the number of thick portions1aextending on the first cone portion1B and the first tail portion1A and the number of folding ridges of the body portion1C are the same, almost the same effect is realized.

Further, even when the number of the thick portions1aextending on the first cone portion1B and the first tail portion1A is a multiple of the number of the folded mountain folds f1of the body portion1C, or even when the number of folded mountain folds f1of the body portion1C is a multiple of the number of the thick portions1aextending on the first cone portion1B and the first tail portion1A, almost the same effect is realized.

Sixth Modification

Next, the balloon-equipped treatment tool for an endoscope of the sixth modification of the first embodiment will be described.

FIG. 11is a schematic front view showing a balloon-equipped treatment tool for an endoscope according to a modified example (sixth modified example) of the first embodiment of the present invention.

As shown inFIG. 11, the balloon-equipped treatment tool10E (balloon-equipped treatment tool for an endoscope) of the fifth modification includes a balloon15instead of the balloon1in the first embodiment. Hereinafter, the features different from the first embodiment will be mainly described.

The balloon15of this modification is different from the balloon1in the first embodiment in that a plurality of thick portions1bare formed so as to extend on the second tail portion1E and the second cone portion1D.

Each thick portion1bhas the same configuration as the thick portion1a. The number of the thick portions1bmay be different from the number of the thick portions1a, but in the example shown inFIG. 11, it is the same as the number of the thick portions1a. The position of the thick portion1ain the circumferential direction and the position of the thick portion1bin the circumferential direction may be different from each other, but in the example shown inFIG. 11, the positions in the respective circumferential directions are the same. Therefore, the extension line connecting the distal ends of the thick portions1aand1bfacing each other in the axial direction along the surface of the balloon15extends in the direction along the central axis O. It is more preferable that the mountain fold portion f1be formed on this extension line.

Since the balloon15has a thick portion1b, it is possible to suppress the occurrence of wrinkles in the second tail portion1E and the second cone portion1D. For example, when the distal end convex portion4receives an external force and the central axis of the distal end convex portion4is inclined with respect to the central axis O of the balloon15, the balloon15is bent near the boundary between the second tail portion1E and the second cone portion1D. However, since the thick portion1bhas the same structure as the thick portion1a, the occurrence of wrinkles is suppressed at the bent portion as in the case of having the thick portion1a.

In particular, when the thick portion1bhas the same configuration as the thick portion1a, the balloon15may fix the second tail portion1E to the distal end of the sheath2and the first tail portion1A to the distal end convex portion4. In this case, since there is no axial orientation in the manufacture and attachment of the balloon15, the balloon15and the balloon-equipped treatment tool10E can be manufactured more easily.

Second Embodiment

Next, the balloon-equipped treatment tool for an endoscope of a second embodiment will be described.

FIG. 12is a schematic cross-sectional view showing an example of a balloon-equipped treatment tool for an endoscope according to the second embodiment of the present invention.

The balloon-equipped treatment tool20(balloon-equipped treatment tool for an endoscope) of the present embodiment shown inFIG. 12includes a sheath25, a shaft28, and a distal end convex portion24, instead of the sheath2, the reinforcing wire3, and the distal end convex portion4in the balloon-equipped treatment tool10of the first embodiment. Further, the balloon-equipped treatment tool20includes a guide wire lumen tube26A, a guide wire lumen hub26B, a fluid-feeding lumen tube27A, and a fluid-feeding lumen hub27B instead of the base5.

Hereinafter, the features different from the first embodiment will be mainly described.

The balloon-equipped treatment tool20of the present embodiment is different from the balloon-equipped treatment tool10in that it can be inserted into the lumen by using the guide wire29placed in the patient's body. For example, as the guide wire29, a nickel titanium alloy, stainless steel, or the like is used.

The sheath25is a long member through which the guide wire29is inserted and introduces the fluid F to the internal space I of the balloon1.

The sheath25is composed of a multi-lumen tube having a guide wire lumen25cand a fluid-feeding lumen25dinside. The guide wire lumen25cand the fluid-feeding lumen25dare each independent lumens and penetrate from the proximal end25ato the distal end25bof the sheath25.

The guide wire lumen25chas an inner diameter through which the guide wire29can be inserted.

The fluid F can be distributed in the fluid-feeding lumen25d.

As the material of the sheath25, the same material as the sheath2in the first embodiment may be used.

The shaft28is a cylindrical member through which a guide wire29extending from the distal end of the guide wire lumen25cis inserted therein. The shaft28is also used for the purpose of supporting the balloon1substantially coaxially with the sheath25. However, the shaft28has flexibility that allows it to bend depending on the magnitude of the external force acting through the lumen into which the balloon-equipped treatment tool20is inserted. Therefore, the shaft28can be curved along the lumen.

The inner diameter of the shaft28is equal to the inner diameter of the guide wire lumen25c. The shaft28is attached to the distal end of the guide wire lumen25cso as to be smoothly connected to the guide wire lumen25c.

The shaft28has a length similar to that of the balloon1and an outer diameter smaller than the inner diameter of each of the first tail portion1A and the second tail portion1E.

The material of the shaft28is not particularly limited as long as it is a material that can obtain the same degree of flexibility as the sheath25. For example, as the material of the shaft28, nylon, polyamide, PTFE (polytetrafluoroethylene), PE (polyethylene), PP (polypropylene) and the like may be used.

The distal end convex portion24is a cylindrical member in which a through-hole24ais formed in the central portion. The inner diameter of the through-hole24ais equal to the inner diameter of the shaft28. The outer diameter of the distal end convex portion24excluding the distal end portion is substantially equal to the inner diameter of the second tail portion1E. The distal end portion of the distal end convex portion24is gradually reduced in diameter and rounded toward the distal end side.

The distal end of the shaft28is connected to the base of the distal end protrusion24so as to be smoothly connected to the through-hole24a.

The guide wire lumen tube26A is a cylindrical member through which the guide wire29extending from the proximal end of the guide wire lumen25cis inserted into the inside. The inner diameter of the guide wire lumen tube26A is equal to the inner diameter of the guide wire lumen25c. The guide wire lumen tube26A is attached to the proximal end portion of the guide wire lumen25cso as to be smoothly connected to the guide wire lumen25c.

At the proximal end of the guide wire lumen tube26A, a guide wire lumen hub26B for guiding the guide wire29to the lumen of the guide wire lumen tube26A is provided.

With such a configuration, inside the balloon-equipped treatment tool20, by providing the guide wire lumen hub26B, the guide wire lumen tube26A, the guide wire lumen25c, the shaft28, and the distal end convex portion24, a lumen L1penetrating from the opening26aof the guide wire lumen hub26B to the through-hole24ais formed. A guide wire29can be inserted through the lumen L1.

The fluid-feeding lumen tube27A is a cylindrical member connected to the proximal end portion of the fluid-feeding lumen25d. The inner diameter of the fluid-feeding lumen tube27A is substantially equal to the inner diameter of the fluid-feeding lumen25d. The fluid-feeding lumen tube27A is attached to the proximal end portion of the fluid-feeding lumen25dso as to be smoothly connected to the fluid-feeding lumen25d.

At the proximal end of the fluid-feeding lumen tube27A, a fluid-feeding lumen hub27B similar to the base5in the first embodiment is provided.

With such a configuration, inside of the balloon-equipped treatment tool20, by the fluid-feeding lumen hub27B, the fluid-feeding lumen tube27A, and the fluid-feeding lumen25d, a lumen L2is formed that penetrates from the opening27aof the fluid-feeding lumen hub27B to the opening25eof the fluid-feeding lumen25dthat opens at the distal end25a. The fluid F can be distributed in the lumen L2.

In the balloon1of the present embodiment, the first tail portion1A is firmly fixed to the distal end portion of the sheath25, and the second tail portion1E is firmly fixed to the proximal end portion of the distal end convex portion24. As a method for fixing the first tail portion1A and the second tail portion1E to the sheath25and the distal end convex portion24, the same fixing method as in the first embodiment can be used.

Inside the balloon1in this embodiment, an internal space I communicating with the lumen L2is formed. Therefore, the fluid F can be introduced to the internal space I through the lumen L2.

The shaft28extends along the center of the internal space I in the balloon1. Both ends of the shaft28in the longitudinal direction are connected to the guide wire lumen25cand the through-hole24awithout communicating with the internal space I. Therefore, the lumen L1forms a through-hole that crosses the internal space I without communicating with the internal space I.

The balloon1of the balloon-equipped treatment tool20of the present embodiment is inserted into the narrowed portion of the patient by a well-known procedure using a guide wire29placed in the patient's body and an endoscope. After being inserted into the narrowed portion, the balloon1can dilate the narrowed portion in the same manner as in the first embodiment. At that time, the operator can perform an angle operation and perform a procedure for expanding the narrowed portion while observing the expanded state of the balloon1in the same manner as in the first embodiment.

Similar to the first embodiment, wrinkles are less likely to occur on the balloon1even if the angle operation is performed. Therefore, according to the balloon-equipped treatment tool20of the present embodiment, it is possible to suppress the occurrence of bump-shaped ridges in the balloon1.

In each of the above embodiments and modifications, a case where a thick portion is formed by blow molding a parison made of a cylindrical tube has been described. However, the method for manufacturing the balloon is not limited to this as long as the thick portion can be formed.

As described in the first embodiment, the type of lumen into which the balloon-equipped treatment tool10is inserted is not limited. However, in the gastrointestinal tract such as the esophagus, pylorus, bile duct, and large intestine, the angle operation is larger than that of the blood vessel, and the bending load is also large. Therefore, the present invention exerts a more remarkable effect when applied to a balloon-equipped treatment tool for gastrointestinal endoscopy. The same applies to the balloon-equipped treatment tool in each modification and the second embodiment.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. It is possible to add, omit, replace, and make other changes to the configuration without departing from the spirit of the present invention.

Further, the present invention is not limited by the above description, but only by the claims of the attachment.

According to each of the above embodiments and modifications, it is possible to provide a balloon-equipped treatment tool for an endoscope capable of suppressing the occurrence of bump-shaped ridges in a balloon.