JP2004275544A - Dilation balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dilation balloon catheter which can be drawn out of an endoscope infallibly and safely after dilating a narrowed or occluded area in an organic lumen, such as a digestive tract. <P>SOLUTION: This dilation balloon catheter comprises a shaft having at least one inner lumen penetrating in a longitudinal direction, a reinforcing body threaded into one lumen in the shaft, a balloon mounted on a distal end of the shaft, and a distal tip. A tip of the reinforcing body should be movable within the inner lumen of the distal tip, which is extended in the inside of the balloon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to dilatation balloon catheters. For example, the present invention relates to a dilatation balloon catheter that dilates a stenosis or occlusion in a living body lumen.
[0002]
[Prior art]
Dilatation balloon catheters are used in a variety of medical procedures and are used to dilate occlusions and stenosis in body lumens. For example, dilatation balloon catheters are used not only in angioplasty to dilate the lumen of a narrowed or stenotic blood vessel due to arteriosclerosis, but also in the gastrointestinal tract caused by a tumor or an anastomotic procedure after its resection. It is also frequently used for dilation of stenosis.
[0003]
Conventional dilatation balloon catheters used for dilatation of gastrointestinal stenosis are roughly classified into the following two types according to the method of use. One is an over-the-wire catheter in which a catheter balloon is placed at a stenosis along a guide wire, and the other is to push a catheter directly without using a guide wire. Is an on-the-wire catheter in which a balloon is placed in a stenosis. The former catheter is used, for example, when expanding a stenosis such as an intestinal tract having a severe degree of bending or a stenosis formed at a bent position by an anastomosis procedure after resection of a tumor, while the latter is a relatively straight line. It is used to dilate a stenosis such as the digestive tract, for example, the esophagus.
[0004]
In recent years, so-called endoscopic dilatation, in which a dilatation treatment using a balloon catheter is performed while observing with a monitor using an endoscope (hereinafter, referred to as direct viewing), is frequently performed. In this case, the balloon catheter is inserted from the forceps port of the endoscope located outside the body into the forceps hole serving as a passage in the endoscope, and inserted through the forceps outlet of the endoscope located inside the body. Perform extended actions. As a guide to the completion of dilatation of the stenosis or occlusion by the balloon, it was observed under direct vision that the stenosis or occlusion was released through the balloon, and it was finally confirmed that the endoscope could pass through the stenosis or occlusion. Above, the surgeon determines that the expansion was successful. Thereafter, the balloon catheter is removed from the endoscope, and the treatment site is observed under the endoscope, and after confirming that there is no problem such as abnormal bleeding, the treatment ends.
[0005]
However, in the conventional on-the-wire balloon catheters shown in Patent Literatures 1 and 2, due to its structure, the re-deflated balloon after pressurized and inflated is bulky and cannot be removed from the endoscope. There was a case. The structure is such that the wire is fixed at the distal tip with the distal joint of the balloon and the proximal end of the shaft with the proximal joint of the balloon, and the wire length inside the balloon is always constant. Structure. On the other hand, as the balloon material of the dilatation balloon catheter, a polymer having low compliance, such as polyethylene terephthalate, is generally selected. However, even when the balloon is pressurized and inflated, the balloon is elongated in the axial direction. Elongation of the balloon during pressurization and inflation is suppressed by a certain length of wire, and as a result, the balloon is retracted. Even when the balloon is deflated, the retraction of the balloon does not disappear, and this portion becomes bulky and catches at the forceps port exit of the endoscope. If the balloon catheter cannot be removed from the endoscope, the operator must remove the balloon catheter from the body together with the endoscope, which not only increases the time to complete the procedure, but also causes bleeding due to dilation. The response was delayed.
[0006]
[Patent Document 1] Japanese Patent No. 2671961 [Patent Document 2] Japanese Patent Application Laid-Open No. 10-513382
[Problems to be solved by the invention]
An object of the present invention is to provide a dilatation balloon catheter that can be reliably and safely removed from an endoscope after performing dilatation treatment of a stenosis or occlusion of a living body lumen such as a digestive tract.
[0008]
[Means for Solving the Problems]
That is, the present invention comprises a shaft having at least one lumen penetrating in the longitudinal direction, a reinforcing member inserted into one lumen of the shaft, a balloon provided at a distal end of the shaft, and a tip. Wherein the distal end of the reinforcing member is movable in a lumen of the distal tip, and the distal tip extends into the balloon. .
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to examples. FIG. 1 schematically shows an on-the-wire type dilatation balloon catheter according to an embodiment of the present invention. 2 shows a sectional view of the shaft of FIG.
FIG. 3 is a diagram showing a cross section of a distal tip of a dilatation balloon catheter according to one embodiment of the present invention, and FIG. 4 is a diagram showing a cross section of a distal tip of a dilatation balloon catheter according to another embodiment of the present invention. FIG. 5 is a cross-sectional view showing a state in which a reinforcing member using a metal tube of a dilatation balloon catheter according to still another embodiment of the present invention is fixed to a distal end portion of a shaft.
[0010]
In the on-the-wire dilatation balloon catheter of FIG. 1, the balloon (1) is hermetically bonded at two parts on the shaft (2) and the distal tip (3). The shaft (2) has one lumen (5) penetrating in the axial direction, and has a coaxial type structure in which the reinforcing body (4) is inserted through the lumen (5). The reinforcing member (4) is for improving the operability of the catheter alone without using a guide wire, and extends from the lumen (5) of the shaft (2) inside the balloon (1) to reinforce it. A tip (3) is attached to the tip of the body (4). The proximal joint (6) of the balloon (1) is attached to the distal end of the shaft (2), and the distal joint (7) is attached to the tip (3). Since the lumen (5) of (2) is open in the balloon (1), an inflation fluid can be sent into the balloon (1) through the lumen (5).
The structure of the catheter tube of the on-the-wire type dilatation balloon catheter according to the present invention is not limited to the above. For example, the catheter tube has a biaxial structure having two lumens, a main lumen and a sub-lumen. Is also good. In this case, the inflation fluid can be sent into the balloon by inserting the reinforcement into one of the lumens and opening at least another lumen into the balloon.
[0011]
The outer diameter of the balloon (1) is preferably 4 to 24 mm, more preferably 10 to 18 mm. The appropriate outer diameter of the balloon (1) for expanding the stenosis or occlusion is generally the inner diameter of the living lumen before stenosis or occlusion, but is less than 4 mm or more than 24 mm. Almost no. Further, the length of the cylindrical portion effective for expanding the balloon (1) is preferably 20 to 80 mm, more preferably 40 to 60 mm. When the diameter is less than 20 mm, it is difficult to dispose the balloon in a stenosis part or an occlusion part, which is not preferable. In addition, there is almost no linear biological lumen exceeding 80 mm, which is not preferable in terms of practicality.
[0012]
The shaft (2) can be made of, for example, a nylon composite material, a polyurethane composite material, or a polyethylene composite material by extrusion molding. For the purpose of providing the shaft (2) with contrast properties, for example, bismuth oxide or A contrast-enhancing substance such as bismuth subcarbonate can also be compounded.
The outer diameter of the shaft (2) is determined by considering the insertability of the endoscope into the forceps port, the lumen (5) that allows the fluid for balloon inflation to pass through without difficulty, and the thickness considering the kink resistance. In order to keep it, 1.5 to 3 mm is preferable. Further, the length of the shaft (2) needs to be larger than the length of the forceps hole so that the procedure can be performed by inserting the shaft into the forceps hole of the endoscope. Therefore, 150 to 200 cm is preferable.
[0013]
In the on-the-wire type dilatation balloon catheter according to the present invention, as shown in FIGS. 3 and 4, the distal tip (3) has a lumen (8) in which the distal end of the reinforcing body (4) can move back and forth. Having. For this reason, even if the balloon (1) expands in the axial direction not less than at the time of pressurized inflation, the balloon (1) does not retract because the reinforcement (4) does not suppress the balloon (1) to a certain length. Therefore, unlike the dilatation balloon catheter having the conventional structure, there is no bulk due to the retraction of the balloon (1) at the time of deflation. Therefore, the dilatation balloon catheter is surely prevented from being caught at the forceps port exit of the endoscope. Can be removed from the endoscope.
[0014]
Further, the distal tip (3) extends into the balloon. This is because, when the balloon (1) expands more than the axial length of the reinforcing body (4) inserted into the balloon when the balloon (1) is pressurized and inflated, the tip of the reinforcing body (4) comes into contact with the balloon. This is to prevent the balloon (1) from being damaged, and to improve safety. Another measure is to make the axial length of the reinforcing body (4) inserted into the balloon sufficiently larger than the axial length of the balloon (1) when pressurized and inflated. The axial length of the reinforcing body (4) located in the tip (3) also increases, and as a result, the axial length of the distal tip (3) becomes unnecessarily large, and when the catheter is inserted into the body, It is not preferable because it is easily caught and the insertability deteriorates.
[0015]
The material of the distal tip (3) used in the on-the-wire type dilatation balloon catheter according to the present invention is preferably a material having a certain degree of flexibility and kink resistance, such as nylon elastomer and polyurethane elastomer. . The shape of the distal end of the distal end tip (3) is preferably rounded in order to prevent perforation of the digestive tract. The shape of the end of the distal tip (3) extending into the balloon is preferably chamfered or rounded to reduce the possibility of damage to the balloon (1). . Further, for the purpose of reducing the bulk, a portion of the distal end tip (3) extending into the balloon may be tapered.
[0016]
As shown in FIG. 4, the tip (3) has a tip (3) for improving kink resistance and reducing the risk of the tip of the reinforcing body (4) protruding from the tip (3). A reinforcement (9) may be provided around the inner cavity (8). Examples of the reinforcing material (9) include a spring, a coil, and a metal mesh.
[0017]
As a material of the reinforcing member (4), a metal is preferable in terms of pushability and cost, and stainless steel such as a high-tensile stainless steel for a spring is more preferable. For the purpose of improving kink resistance, for example, a superelastic metal such as nitinol (a nickel-titanium alloy) may be used. Further, the reinforcing body (4) is preferably a single wire, but the present invention is not limited to this, and may be, for example, a stranded wire. When the reinforcing member (4) is a stranded wire, kink resistance can be improved without using a superelastic metal. Furthermore, it is preferable that the tip of the reinforcing member (4) has a round shape.
[0018]
For fixing the reinforcing body (4) to the distal end of the shaft (2), for example, a metal tube (10) is attached to a lumen on the distal side of the shaft (2), and the reinforcing body (4) is attached thereto. ) Can be performed by soldering or brazing. When such a fixing method is used, as shown in FIG. 5, the distal end of the metal tube (10) is further used for the purpose of reducing the bulk of the proximal joint portion (6) of the balloon (1). The proximal joint (6) of the balloon (1) may be attached to the proximal side and the distal end of the shaft (2) may be attached to the proximal side of the metal tube (10).
[0019]
【The invention's effect】
As is clear from the above, the dilatation balloon catheter according to the present invention is extremely useful as a medical device that can be reliably and safely removed from an endoscope after performing a dilatation treatment of a stenosis or obstruction of a living body lumen such as a digestive tract. is there.
[Brief description of the drawings]
FIG. 1 schematically shows an on-the-wire type dilatation balloon catheter according to an embodiment of the present invention.
FIG. 2 shows a cross-sectional view of a shaft of an on-the-wire type dilatation balloon catheter according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of a distal tip of an on-the-wire type dilatation balloon catheter according to an embodiment of the present invention.
FIG. 4 shows a cross-sectional view of the distal tip of an on-the-wire dilatation balloon catheter according to another embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a state in which a reinforcing member of an on-the-wire type dilatation balloon catheter according to yet another embodiment of the present invention is fixed to a distal end portion of a shaft.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 balloon 2 shaft 3 distal tip 4 stiffener 5 lumen 6 proximal joint 7 distal joint 8 lumen (of distal tip) 9 reinforcement 10 metal tube

Claims (1)

A dilatation balloon catheter comprising a shaft having at least one lumen penetrating in a longitudinal direction, a reinforcement inserted through one lumen of the shaft, a balloon provided at a distal end of the shaft, and a distal tip. Wherein the distal end of the reinforcing member is movable in a lumen of the distal tip, and the distal tip extends into the balloon.

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