JPH08257139A - Balloon catheter - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a balloon catheter which is not easily damaged even after long-term use in endovascular treatment and has excellent abrasion resistance. A balloon catheter 2 having a balloon membrane 22 made of a tubular thin film and a catheter tube 6 having a distal end to which the proximal end of the balloon membrane 22 is joined. The catheter tube 6 is a tubular body having a lumen 14 that communicates from the distal end to the proximal end. A fluid can be introduced into the balloon membrane 22 through the lumen 14. At least two convex portions 50 are formed on the outer wall of the balloon membrane 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention expands a flow path in a body cavity by inserting the balloon into a body cavity such as a blood vessel, or alternately repeats expansion and contraction of the balloon to prevent pulsation of the heart. The present invention relates to a balloon catheter used for treatment such as assistance.

[0002]

2. Description of the Related Art A balloon provided in a conventional balloon catheter used for expanding a body cavity or assisting the heart is made of a tubular thin film, and its outer wall has a smooth cylindrical surface. ing.

[0003]

However, when a balloon catheter equipped with a balloon according to such a conventional example is inserted into a blood vessel and a treatment such as dilating the blood vessel or assisting the heart (balloon pumping) is performed, the balloon However, there was a problem that the balloon was easily damaged by rubbing against the inner wall of the blood vessel and could not be used for a long time.

A first object of the present invention is to provide a balloon catheter which is not easily damaged even if it is used for a long period of time in endovascular treatment and is excellent in abrasion resistance. A second object of the present invention is to provide a balloon catheter that can effectively prevent thrombus generation due to blood retention.

A third object of the present invention is to provide a balloon catheter capable of effectively preventing kinking of the balloon even in a bent body cavity.

[0006]

Thus, according to the present invention, (1) a balloon catheter having a balloon, a catheter tube and a rod-shaped body, the catheter tube having a lumen communicating from the distal end to the proximal end. A tubular body having; a rod-shaped body capable of being inserted through a lumen of the catheter tube, a distal end of the rod-shaped body protruding further than a distal end of the catheter tube, and a balloon made of a tubular thin film, Two or more protrusions are formed on the outer wall of the thin film, and one end of the thin film is joined to the distal end of the catheter tube and the other end is joined to the distal end of the rod-shaped body to cover the rod-shaped body protruding from the catheter tube. The volume of the balloon is fixed by feeding the fluid into the space formed between the inner wall of the thin film and the outer wall of the rod through the space formed between the inner wall of the catheter tube and the outer wall of the rod. Expansion It is obtained as: balloon catheter, wherein there is provided that.

The following are provided as preferred embodiments of the balloon catheter according to the present invention. (2) The balloon catheter according to (1), wherein the rod-shaped body is a tubular body having a lumen communicating from the distal end to the proximal end. (3) The balloon catheter according to the above (1), wherein the thin film forming the balloon has a film thickness that is substantially the same in the portion where the convex portion is formed and the portion where the convex portion is not formed. (4) The protrusion formed on the outer wall of the thin film is an embossed protrusion,
The balloon catheter according to (1) above, which is a convex portion which is continuously or intermittently long in the axial direction, a spiral convex portion, or a convex portion which is formed by forming a cross-section into a deformed tubular shape. (5) The above-mentioned (1), wherein the convex portion formed on the outer wall of the thin film is a spiral convex portion or a circumferential ring-shaped convex portion.
Balloon catheter.

In the balloon catheter according to the present invention, the rod-shaped body may be one that can be inserted through the lumen of the catheter tube. As the rod-shaped body, metal wire material such as stainless wire; glass wire or resin wire material such as optical fiber;
Examples thereof include a tubular body (hereinafter, sometimes referred to as an inner tube) having a lumen that communicates from its distal end to its proximal end. From the viewpoint of collecting body fluid such as blood from the distal end of the balloon catheter or detecting the pressure in the body cavity,
It is preferable to use the inner tube.

In the present invention, the two or more convex portions formed on the outer wall of the thin film forming the balloon (hereinafter sometimes referred to as the balloon membrane) are used in a broad sense, and are embossed convex portions and axial directions. In addition to a continuous or intermittently long convex portion, a circumferentially continuous or intermittent ring-shaped convex portion, a spiral convex portion, a convex portion formed by forming a cross-section into a deformed tubular shape , Or a convex portion formed by combining these. The convex portion formed by forming the cross-section into a deformed tubular shape is a shape in which, for example, two or more arc surfaces having different central axes are formed on the outer circumference of the balloon membrane.

The film thickness of the balloon film may be made substantially equal in the portion where the convex portion is formed and the portion where the convex portion is not formed. However, in order to enhance the abrasion resistance of the balloon film, the convex portion is formed. It is preferable that the portion where the portion is formed is thicker than the portion where the convex portion is not formed.

[0011]

Since the balloon catheter according to the present invention has a convex portion formed on the outer wall of the balloon membrane, when the balloon catheter is inserted into a blood vessel and a treatment such as blood pumping or vasodilation is performed, the balloon membrane of the balloon membrane is Only the convex portion of the outer wall contacts the inner wall of the blood vessel. Therefore, the abrasion due to the friction with the inner wall is reduced, and the durability of the balloon membrane is improved.

Further, since the variable range of the expansion volume (hereinafter, sometimes referred to as volume) of the balloon provided in the conventional balloon catheter is narrow, it is necessary to select a balloon catheter having an expansion volume corresponding to the size of the patient. is there. In particular, intra-aortic balloon pumping (Intra Aort
In ic balloon pumping (hereinafter abbreviated as “IABP method”), the maximum outer diameter and capacity of the balloon when expanded are important factors. In this treatment, a balloon with the maximum outer diameter that matches the blood vessel of the patient is used. It is important to use and repeat the inflation and deflation of the balloon with the appropriate volume. Therefore, several kinds of balloon catheters having different volumes (or maximum outer diameters) had to be stocked in the medical field.

In the balloon catheter of the present invention, when the thickness of the portion where the convex portion is formed on the outer wall of the balloon membrane is almost equal to that of the other portion, the uneven portion is also formed on the inner wall of the balloon. When a fluid is fed into the balloon membrane at a predetermined pressure, the balloon membrane swells according to the irregular shape and expands to the maximum outer diameter determined by the height of the convex portion. For patients whose balloon membrane volume at that pressure is sufficient,
Treat with that pressure. For patients who need a larger volume, when the fluid is fed into the balloon membrane at a higher pressure, the part where the outer wall does not have a protrusion (the protrusion on the inner wall) expands outward (wrinkles grow). To extend). As a result, the balloon membrane internal volume can be increased without changing the maximum outer diameter of the balloon membrane.
Therefore, the balloon catheter of the present invention has a wide applicable volume range, and the complexity of selecting the balloon catheter in the medical field is reduced.

In the present invention, such as an embossed convex portion, a convex portion continuously or intermittently long in the axial direction, a spiral convex portion, a convex portion formed by forming a cross section into a deformed tubular shape, etc. In addition, when a gap communicating with the body cavity such as a blood vessel in the axial direction is formed on the outer periphery of the balloon membrane when expanded, it has the following action. That is, since body fluid such as blood flows through the gap even when the balloon membrane is expanded,
It is possible to effectively suppress the generation of thrombus due to the retention of blood.

With a balloon catheter having a balloon membrane having spiral protrusions or circumferential ring-shaped protrusions, even if the balloon membrane is inserted into a bent body cavity, the bending stress applied to the balloon membrane is effective. It is possible to effectively prevent the kink of the balloon membrane from being damaged.

[0016]

The balloon catheter according to the present invention will be described below in detail with reference to the embodiments and examples shown in the drawings. FIG. 1 is a schematic cross-sectional view of a main part of a balloon catheter according to an embodiment of the present invention, and FIG. 2 is a schematic view showing an example of use of the balloon catheter of the embodiment.

First Embodiment A balloon catheter 2 according to the embodiment shown in FIG. 1 is used for IABP treatment, for example, and has a balloon 4 that expands and contracts in accordance with the pulsation of the heart.
The balloon 4 is composed of a tubular balloon film 22 having a film thickness of about 100 to 150 μm. The balloon membrane 22 is preferably made of a material having excellent bending fatigue resistance, and is formed of, for example, a material such as polyurethane, silicone, soft polyethylene, soft polyamide, or soft polyester. Particularly, a material made of polyurethane suppresses the occurrence of thrombus. It is suitable because it has high performance and wear resistance. The outer diameter and the length of the balloon membrane 22 are determined according to the inner volume of the balloon membrane 22 that greatly affects the assisting effect of the cardiac function, the inner diameter of the arterial blood vessel, and the like. The balloon membrane 22 usually has an inner volume of 30 to 50 cc, an outer diameter of 14 to 16 mm when expanded, and a length of 210 to 270 mm.

A tapered distal end side taper portion 24 is formed at the distal end of the balloon membrane 22, and the most distal end of the balloon membrane 22 is attached to the outer periphery of the distal end of the inner tube 10 via a short tube or directly. It is attached by means such as heat fusion or adhesion. At the proximal end of the balloon membrane 22, a tapered proximal end side taper portion 2 is formed.
6 is formed, the proximal end of which is joined to the distal end of the catheter tube 6 via a direct contrast marker made of metal tube or directly. Through the first lumen 14 formed inside the catheter tube 6, inside the balloon membrane 22,
The pressurized fluid is introduced or discharged to cause the balloon membrane 22 to expand or contract. The balloon film 22 and the catheter tube 6 are joined by heat fusion or adhesion with an adhesive such as an ultraviolet curable resin.

The distal end of the inner tube 10 projects further than the distal end of the catheter tube 6. The inner tube 10 is a balloon membrane 22.
Also, the catheter tube 6 is inserted through the inside in the axial direction. The proximal end of the inner pipe 10 is adapted to communicate with a second port 18 of the branch portion 8 described later. A second lumen 12 that does not communicate with the first lumen 14 formed inside the balloon membrane 22 and inside the catheter tube 6 is formed inside the inner tube 10. As will be described later, the inner tube 10 is adapted to send the blood pressure taken in at the open end 20 at the distal end to the second port 18 of the branch portion 8 and measure the blood pressure fluctuation from there.

When inserting the balloon catheter 2 into an artery, the second lumen of the inner tube 10 located in the balloon membrane 22 is also used as a guide wire insertion lumen for inserting the balloon membrane 22 into the artery conveniently. Then, the balloon membrane 22 is folded and wound around the outer circumference of the inner tube 10. Inner tube 1
0 may be made of the same material as the catheter tube 6, for example, a synthetic resin tube of polyurethane, polyvinyl chloride, polyethylene, polyamide, polyimide or the like, a metal spring reinforcing tube, a stainless thin tube, or the like. A stainless wire, a nickel-titanium alloy wire, or the like may be used as the reinforcing material. The inner diameter of the inner tube 10 is not particularly limited as long as it can pass the guide wire, and is, for example, 0.15 to 1.5 mm, preferably 0.5 to 1 mm. The wall thickness of this inner tube 10 is 0.1.
~ 0.4 mm is preferred. The total length of the inner tube 10 is determined according to the axial length of the balloon catheter 2 inserted into the blood vessel, and is not particularly limited, but is, for example, 500 to 1.
It is about 200 mm, preferably about 700 to 1000 mm.

The catheter tube 6 is preferably made of a material having a certain degree of flexibility, such as polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride. (PVC), cross-linked ethylene-vinyl acetate copolymer, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, silicone rubber, natural rubber and the like can be used, and preferably polyurethane, polyethylene, polyamide or polyimide is used. . The outer diameter of the catheter tube 6 may be uniform in the axial direction, but a stepped portion or a tapered portion is formed in the middle so that it is small in the vicinity of the balloon membrane 22 side and large in the other portion (proximal end side). Is also good. By increasing the cross section of the flow path of the first lumen 14, it is possible to improve the responsiveness of expanding and contracting the balloon membrane 22. The inner diameter of the catheter tube 6 is preferably 1.5 to 4.0 mm, and the wall thickness of the catheter tube 6 is preferably 0.05 to 0.4 mm. The length of the catheter tube 6 is preferably about 300 to 800 mm.

The proximal end of the catheter tube 6 is connected to a branch portion 8 which is placed outside the patient's body. The branch portion 8 is formed separately from the catheter tube 6 and fixed by means such as heat fusion or adhesion. A first port 16 for introducing or discharging a pressure fluid into the first lumen 14 in the catheter tube 6 and the balloon membrane 22 and a second port communicating with the second lumen 12 in the inner tube 10 at the branch portion 8. And 18 are formed. The branch portion 8 is formed of a thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyacrylate, methacrylate-butylene-styrene copolymer.

The first port 16 is connected to, for example, a pump device 28 shown in FIG. 2, and the pump device 28 introduces or discharges a fluid pressure into the balloon membrane 22. The fluid to be introduced is not particularly limited, but helium gas or the like having a low viscosity and a small mass is used so that the balloon membrane 22 expands or contracts quickly in response to the driving of the pump device 28. As the pump device 28, for example, a device disclosed in Japanese Patent Publication No. 2-39265 is used.

The second port 18 is connected to the blood pressure fluctuation measuring device 29 shown in FIG. 2 and is capable of measuring the fluctuation of blood pressure in the artery taken from the open end 20 at the distal end of the balloon membrane 22. Based on the change in blood pressure measured by the blood pressure measurement device 29, the pump device 28 is controlled according to the pulsation of the heart 1 shown in FIG.
To expand and contract.

In this embodiment, as shown in FIG. 1, a large number of embossed protrusions 50 are formed on the outer periphery of the balloon film 22. Each protrusion 50 is a substantially hemispherical protrusion, and its height h is not particularly limited, but is preferably 0.05 to 2 mm.
It is a degree. These convex portions 50 may be arranged on the outer wall of the balloon membrane 22 at substantially equal intervals, but they may be arranged at unequal intervals. The pitch between the protrusions 50 arranged at substantially equal intervals (the distance from the center of the protrusion to the center of another adjacent protrusion) is not particularly limited, but is preferably about 1 to 10 mm.

The film thickness of the balloon film may be substantially equal between the portion where the convex portions 50 are located and the portion where the convex portions 50 are not located. However, as shown in FIG. 1, in the portion where the convex portions 50 are located. It is preferable that the film thickness is thick and the inner wall is smooth. In that case, the abrasion resistance of the balloon film 22 can be improved.

Each taper portion 24, 2 at both ends of the balloon membrane
It is not always necessary to form the convex portion 50 on the outer wall of 6, but it may be formed as shown in FIG. The balloon film 22 having such convex portions 50 can be easily formed by a dip forming method or the like in which a mold for forming the balloon film 22 is dipped in a material solution and then pulled up.

In the balloon catheter 2 according to this embodiment, since the outer wall of the balloon membrane 22 has the convex portion 50, when the balloon catheter 2 is inserted into an arterial blood vessel as shown in FIG. Only the protrusion 50 on the outer wall of the membrane 22 comes into contact with the inner wall of the blood vessel. Therefore, abrasion due to friction with the inner wall of the blood vessel is reduced, and the durability of the balloon membrane 22 is improved. In the IABP treatment, since the balloon membrane 22 is positioned inside the blood vessel, expansion and contraction are repeated in synchronization with the heartbeat, a high degree of durability is required. The balloon catheter 2 according to the present embodiment withstands such a severe demand.

Further, in the balloon catheter of the present embodiment, a gap is formed on the outer circumference of the balloon membrane 22 when it is inflated so as to communicate with the blood vessel in the axial direction. As a result, blood is passed through the gap even when the balloon membrane is inflated. Since it flows, it is possible to effectively suppress the generation of thrombus and the like due to the retention of blood.

Second Embodiment The balloon catheter according to the present embodiment is used for methods such as percutaneous coronary angioplasty (PTCA), dilatation of blood vessels of limbs, dilatation of upper ureter, and renal vasodilation. A balloon catheter used to dilate a stenosis formed in a blood vessel or other body cavity. The overall configuration of this balloon catheter is similar to that shown in FIG. 1, but the following portions are slightly different. In the following description, only the parts different from the above-described embodiment will be described, and the other parts are the same, so the description thereof will be partially omitted.

In the present embodiment, the outer diameter of the catheter tube 6 may be uniformly 0.6 to 1.2 mm in the axial direction, but it is set to about 0.6 to 1.0 mm in the vicinity of the connecting portion with the balloon membrane 22. On the branch portion 8 side, the outer diameter may be set to about 0.8 to 1.2 mm, and the outer diameter may be changed intermittently or continuously in the axial direction.
In addition, the wall thickness of the catheter tube 6 is 0.05 evenly in the axial direction.
It is preferably about 0.15 mm.

In the present embodiment, the material forming the balloon membrane 22 is preferably a material having a certain degree of flexibility, such as polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate. Copolymers, polyvinyl chloride (PVC), cross-linked ethylene-vinyl acetate copolymers, polyurethanes, polyamides, polyamide elastomers, polyimides, polyimide elastomers, silicone rubbers, natural rubbers and the like can be used, and preferably polyethylene, polyethylene terephthalate. , Polyamide.

The balloon membrane 22 has tapered portions 2 at both ends.
It is composed of a tubular thin film having 4, 26, and its film thickness is not particularly limited, but is 15 to 200 μm, preferably about a hundred and several tens of μm. The outer diameter of the balloon membrane 22 when expanded is determined by factors such as the inner diameter of the blood vessel, and is 1.5 to 4.0.
mm is preferable. The axial length of the balloon membrane 22 is determined by factors such as the size of the intravascular stenosis and is usually 15 to 50 mm, preferably 20 to 40 mm. The balloon membrane 22 before expansion is folded and wrapped around the inner tube 10 and has a diameter equal to or smaller than the outer diameter of the catheter tube 6.

Also in this embodiment, as in the first embodiment, a large number of protrusions 50 are formed on the outer periphery of the balloon membrane 22. A radiopaque marker may be attached at one or more locations around the inner tube 10 located in the balloon membrane 22. As the marker, for example, a metal tube made of gold, platinum, tungsten, iridium, or an alloy thereof, a metal spring, or the like can be used. By attaching this marker around the inner tube 10 in the balloon membrane, the position of the balloon 4 and the length of the expanded portion of the balloon can be detected under fluoroscopy during use of the balloon catheter 2.

The first port 16 of the branch portion 8 is an expansion port in this embodiment, and the pressure fluid is introduced into the first lumen 14 through the expansion port. The pressure fluid to be introduced is not particularly limited, but for example, a 50/50 mixed aqueous solution of a radiopaque dye and salts is used. The reason why the radiopaque dye is included is to use radiation to image the positions of the balloon 4 and the catheter tube 6 when the balloon catheter 2 is used. The pressure of the pressure fluid for inflating the balloon 4 is not particularly limited, but is 3 to 12 atm, preferably about 4 to 8 atm in absolute pressure.

For the PTCA, the second port 18 of the branch portion 8 is a guide port 18 for inserting a guide wire.
Becomes Next, using the balloon catheter 2 of the embodiment shown in FIG. 1 as a balloon catheter for expanding a body cavity,
A method of performing CA treatment will be described.

First, the air inside the balloon catheter 2 is removed as much as possible. Therefore, the second port 18 of the branching unit 8
A liquid such as physiological saline is put into the second lumen 12 in the inner tube 10 to replace the air in the second lumen 12. Further, a suction / injection means such as a syringe is attached to the first port 16 of the branch portion 8, a liquid such as a blood contrast agent (containing iodine, for example) is put in the syringe, suction and injection are repeated, and the first lumen 14 and The air in the balloon membrane 22 is replaced with a liquid.

To insert the balloon catheter 2 into an arterial blood vessel, first, a guide catheter guide wire (not shown) is inserted into the blood vessel by the Seldinger method or the like so that the tip of the guide wire reaches near the heart, for example. . Then, the guide catheter is inserted into the arterial blood vessel along the guide wire for the guide catheter, and the tip thereof is positioned at the coronary artery entrance of the heart having a stenosis. The stenosis is
For example, it is formed by thrombus or arteriosclerosis.

Next, only the guide wire for the guide catheter is pulled out, a guide wire for a balloon catheter which is thinner than that is inserted along the guide catheter, and the tip thereof is inserted to a position where it passes through the stenosis. After that, the end of the guide wire is inserted into the open end 20 of the balloon catheter 2 shown in FIG. 1, passed through the second lumen 12 of the inner tube 10, and the balloon membrane 22 is folded. Pass through. Then, as shown in FIG. 3, the balloon membrane 22 of the balloon catheter 2 is inserted up to the front of the narrowed portion 36. Alternatively, after pulling out the guide wire for the guide catheter from the guide catheter, the second port 18 of the branched portion 8
A balloon catheter having a guide wire inserted into the lumen 12 may be inserted from the proximal end of the guide catheter to guide the balloon membrane 22 into the coronary artery, and the distal end of the guide wire 42 may be inserted to a position passing through the stenosis 36. .

After that, as shown in FIG. 3A, the distal end of the balloon membrane 22 formed at the tip of the balloon catheter 2 is inserted along the guide wire 42 between the narrowed portions 36. Next, as shown in FIGS. 3B and 3C, while observing the position of the balloon film 22 with an X-ray fluoroscope,
The balloon membrane 22 is accurately positioned at the center of the narrowed portion 36. By inflating the balloon membrane 22 at that position, the narrowed portion 36 of the blood vessel 34 can be widened and good treatment can be performed. The balloon membrane 22 is inflated by injecting a liquid such as a contrast agent into the balloon membrane 22 from the first port 16 shown in FIG. 1 through the first lumen 14.

The extension time is not particularly limited, but is, for example, about 1 minute. After that, the liquid is quickly drained from the balloon film 22 to contract the balloon film, and the blood flow on the peripheral side of the expanded stenosis 36 is secured. Balloon membrane 2
The expansion of 2 is usually performed once for the same constricted portion 36, but may be performed multiple times depending on the condition of the constricted portion 36.

In the balloon catheter 2 for expanding a body cavity according to the present embodiment, since the outer wall of the balloon membrane 22 has the protrusion 50, the balloon catheter 2 is inserted into a blood vessel as shown in FIG. Only the protrusion 50 on the outer wall of the membrane 22 contacts the inner wall of the blood vessel. Therefore, abrasion due to rubbing against the inner wall of the blood vessel is reduced, and the durability of the balloon membrane 22 is improved.

Further, in the balloon catheter of the present embodiment, since a gap communicating with the blood vessel in the axial direction is formed on the outer periphery of the balloon membrane 22 at the time of dilation, even when the balloon membrane 22 is dilated, the gap is Since blood flows, it is possible to effectively suppress the generation of thrombus and the like due to the retention of blood.

Third Embodiment Hereinafter, balloon catheters according to various embodiments of the present invention will be described, but the description of the portions overlapping the above-mentioned embodiments will be omitted and only the different portions will be described. Also, each of the balloon catheters shown below can be used for balloon pumping treatment such as IABP treatment and body cavity expansion treatment such as PTCA treatment by changing the material or size of each component.

In the balloon catheter 2a according to the embodiment shown in FIG. 4, a spiral projection 50a is formed on the outer circumference of the balloon membrane 22a. The height of the convex portion 50a is, for example, 0.05 to 3 mm. Further, on the inner wall of the balloon film 22a at a position corresponding to the convex portion 50a, a concave portion 60 is spirally formed so as to correspond to the convex portion.

In this balloon catheter 2a, since the outer wall of the balloon membrane 22a has a convex portion 50a, when the balloon catheter 2a is inserted into a blood vessel and a treatment such as blood pumping or vasodilation is performed, the outer wall of the balloon membrane 22a. Only the convex portion 50a of the contact portion contacts the inner wall of the blood vessel. For this reason,
The friction degree due to friction with the inner wall of the blood vessel is reduced, and the durability of the balloon membrane 22a is improved.

Further, in this balloon catheter 2a,
Through the lumen of the catheter tube 6, the balloon membrane 22a
When the fluid is sent into the inside with a predetermined pressure, the balloon membrane 22a
Swells according to the above-mentioned concavo-convex shape and expands to the maximum outer diameter determined by the height of the convex portion 50a (the concave portion 60 of the inner wall). For patients whose balloon membrane volume at that pressure is sufficient, treatment at that pressure is performed. For patients who need a larger volume, when the fluid is fed into the balloon membrane at a higher pressure, the balloon membrane is deformed so that its cross section becomes a perfect circle, and the convex portion is not formed on the outer wall. The (convex portion on the inner wall) spreads outward (expands so that wrinkles extend). As a result, the balloon membrane internal volume can be increased without changing the maximum outer diameter of the balloon membrane.
Therefore, the balloon catheter of the present invention has a wide applicable volume range, and the complexity of selecting the balloon catheter in the medical field is reduced.

Further, in this balloon catheter, even when the balloon membrane 22a is expanded, the body fluid such as blood flows through the gap communicating with the axial direction of the body cavity, so that the generation of thrombus due to the retention of blood can be effectively suppressed. . Further, in this balloon catheter, the balloon membrane 22a
Even when the balloon membrane is inserted into a bent body cavity, the bending stress applied to the balloon membrane 22a is effectively absorbed, and the balloon membrane 2a
2a is less likely to cause kinking, and the balloon damage and poor expansion associated therewith can be effectively prevented.

Fourth Embodiment As shown in FIG. 5, in this balloon catheter 2b,
A ring-shaped convex portion 50a is formed continuously in the axial direction on the outer periphery of the balloon membrane 22a.
The outer periphery of 2a has a bellows shape. The height h of each convex portion 50b is, for example, 0.05 to 3 mm. Further, on the inner wall of the balloon membrane 22a at a position corresponding to the convex portion 50b,
A concave portion is formed so as to correspond to the convex portion.

In this balloon catheter 2b, a gap with the body cavity is formed when the balloon membrane 22b is expanded, but the same action as that of the third embodiment is achieved except that the gap does not communicate in the axial direction. Fifth Embodiment As shown in FIG. 6, in this balloon catheter 2c,
The cross-section of the balloon membrane 22c is shaped like two arcs are combined, and two convex portions 50c, 50c are formed continuously in the axial direction of the balloon membrane 22c. The outer diameter D of each arc is 10 to 18 mm, and the maximum diameter d when expanded is 14 to 20 mm. D / d is preferably 70 to 90%.

In this balloon catheter 2c, the convex portion 50c is formed on the outer wall of the balloon membrane 22c. Therefore, when the balloon catheter 2c is inserted into a blood vessel and a treatment such as blood pumping or vasodilation is performed, the balloon contacting the inner wall of the blood vessel is obtained. The outer wall of the film 22c is only the protrusion 50c. Therefore, the degree of friction due to friction with the inner wall of the blood vessel is reduced, and the durability of the balloon film 22c is improved.

Also, since the balloon catheter 2c has a wide applicable volume range like the balloon catheter 2a, the complexity of selecting the balloon catheter in the medical field is small. Further, in the balloon catheter 2c, even when the balloon membrane 22c is expanded, the body fluid such as blood flows through the gap communicating with the axial direction of the body cavity, so that the generation of thrombus or the like due to the retention of blood can be effectively suppressed.

Sixth Embodiment As shown in FIG. 7, in this balloon catheter 2d,
The cross-section of the balloon film 22d has a shape that is formed by combining three circular arcs, and the three convex portions 50d, 50d, 5
0d is formed continuously in the axial direction of the balloon film 22d. The diameter D of each arc is 8 to 18 mm, and the maximum diameter d when expanded is 14 to 20 mm. D / d is preferably 50 to 90%.

This balloon catheter 2d has the same operation as the balloon catheter 2c shown in FIG. Seventh Embodiment As shown in FIG. 8, in this balloon catheter 2e,
The cross-section of the balloon membrane 22e has a shape that is formed by combining five circular arcs, and the five convex portions 50e, 50e, 5
0e, 50e, 50e are formed continuously in the axial direction of the balloon film 22e. The diameter D of each arc is 3 to 16 mm, and the maximum diameter d when expanded is 14 to 20 mm. D / d is preferably 20 to 80%.

The balloon catheter 2e has the same operation as the balloon catheter 2c shown in FIG. Eighth Embodiment As shown in FIG. 9, in this balloon catheter 2f,
The cross section of the balloon membrane 22f is substantially triangular, and each of the apex portions has three convex portions 50f, 50f, 50f having an arc-shaped cross section.
Are continuously formed in the axial direction of the balloon film 22f.

This balloon catheter 2f has the same operation as the balloon catheter 2c shown in FIG. Ninth Embodiment As shown in FIG. 10, in this balloon catheter 2g, the cross section of the balloon membrane 22g is substantially oval,
Two convex portions 50g, 50g having an arcuate cross-section are formed continuously on each top in the axial direction of the balloon membrane 22g.

This balloon catheter 2g has the same operation as the balloon catheter 2c shown in FIG. Next, the present invention will be described with reference to more specific examples. Example 1 A balloon catheter 2 as shown in FIG. 1 was prepared. The thin film forming the balloon film 22 has a film thickness of 0.1 m.
When the polyurethane membrane of m was used, the outer diameter of the balloon portion when expanded was 15 mm, the inner volume of the balloon portion was 30 cc, and the axial length thereof was 230 mm. The height h of the convex portion 50 formed on the outer wall of the balloon membrane 22 is 1 mm.
And the pitch between the convex portions was 5 mm.

As the inner tube 10, a polyamide thin tube having an outer diameter of 1.5 mm and a wall thickness of 0.3 mm was used. The total length of the inner tube 10 was 830 mm. As the catheter tube 6, a polyurethane tube having a length of 550 mm is used, the outer diameter of which is 3.0 mm and the wall thickness is 0.25.
mm.

As the branching part, the branching part 8 shown in FIG. 1 was used. This balloon catheter has an inner diameter of 20 mm and a length of 3
It was 50 mm and was passed through an acrylic pseudo blood vessel whose inner surface was covered with cement, and expansion and contraction were repeated at 80 cycles per minute for 14 days in the pseudo blood vessel to observe the condition (durability) of the balloon membrane.

The results are shown in Table 1.

[0061]

[Table 1]

Comparative Example 1 Except that the convex portion 50 is not formed on the outer periphery of the balloon membrane 22,
A balloon catheter was prepared in the same manner as in Example 1, and the durability of the balloon membrane was examined under the same conditions as in Example 1. The results are shown in Table 1.

Evaluation As shown in Table 1 above, it was confirmed that the balloon catheter according to the present example has significantly improved durability as compared with the comparative example. The present invention is not limited to the above-mentioned embodiments, but can be modified in various ways within the scope of the present invention.

[0064]

As described above, according to the present invention, since the outer wall of the balloon membrane has a convex portion, when this balloon catheter is inserted into a blood vessel and a treatment such as balloon pumping or vasodilation is performed. Only the convex portion of the outer wall of the balloon membrane contacts the inner wall of the blood vessel. Therefore, the abrasion due to the friction with the inner wall of the body cavity is reduced, and the durability of the balloon membrane is improved.

In the balloon catheter of the present invention, when the thickness of the convex portion of the balloon membrane and the other portion are substantially equal, the volume is changed without changing the maximum outer diameter of the balloon membrane when it is expanded. Therefore, the applicable volume range is widened, and the complexity of selecting a balloon catheter in the medical field is reduced.

In the present invention, such as an embossed convex portion, a convex portion continuously or intermittently long in the axial direction, a spiral convex portion, a convex portion formed by forming a cross-section into a deformed tubular shape, etc. In addition, in the case where a gap communicating with the body cavity such as a blood vessel in the axial direction is formed on the outer circumference of the balloon membrane when expanded, the following effects are obtained. That is, even when the balloon membrane is expanded, the body fluid such as blood flows through the gap communicating with the axial direction of the body cavity, so that the generation of thrombus and the like due to the retention of blood can be effectively suppressed.

In the balloon catheter of the present invention having a balloon membrane having spiral protrusions or circumferential ring-shaped protrusions, even when the balloon membrane is inserted into a bent body cavity, the balloon membrane is bent. It is possible to effectively absorb stress and effectively prevent kinking of the balloon membrane.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part of a balloon catheter according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an example of use of the balloon catheter of the same embodiment.

3 (A) to 3 (C) are schematic views showing an example of use of a balloon catheter according to another embodiment of the present invention.

FIG. 4 is a side view of a main part of a balloon catheter according to another embodiment of the present invention.

FIG. 5 is a side view of a main part of a balloon catheter according to still another embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a balloon catheter according to still another embodiment of the present invention.

FIG. 7 is a cross-sectional view of a main part of a balloon catheter according to yet another embodiment of the present invention.

FIG. 8 is a sectional view of a main part of a balloon catheter according to still another embodiment of the present invention.

FIG. 9 is a sectional view of a main part of a balloon catheter according to still another embodiment of the present invention.

FIG. 10 is a sectional view of a main part of a balloon catheter according to still another embodiment of the present invention.

[Explanation of symbols]

 2, 2a to 2g ... Balloon catheter 4 ... Balloon section 6 ... Catheter tube 8 ... Branch section 10 ... Inner tube 12 ... Second lumen 14 ... First lumen 22, 22a-22g ... Balloon membrane 50, 50a-50g ... Convex section

Claims (1)

[Claims] 1. A balloon catheter having a balloon, a catheter tube and a rod-shaped body, wherein the catheter tube is a tubular body having a lumen communicating from a distal end to a proximal end; and the rod-shaped body is a lumen of the catheter tube. The rod-shaped body has a distal end projecting farther than the distal end of the catheter tube, and the balloon is made of a tubular thin film, and two or more protrusions are formed on the outer wall of the thin film. , One end of the thin film is joined to the distal end of the catheter tube and the other end is joined to the distal end of the rod-shaped body and is fixed so as to cover the rod-shaped body protruding from the catheter tube. A balloon container capable of expanding the volume of a balloon by sending a fluid through a space formed between the outer wall and the inner wall of the thin film to the space formed between the outer wall of the rod-shaped body; Ether.