JP4191517B2 - Dilatation balloon catheter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to dilatation balloon catheters. For example, the present invention relates to an dilatation balloon catheter that expands a stenosis or occlusion in a living body lumen.
[0002]
[Prior art]
Dilatation balloon catheters are used in various medical procedures, and are used to dilate obstructions or strictures in body lumens. For example, dilatation balloon catheters are used in angioplasty to dilate the lumens of narrowed or narrowed blood vessels due to arteriosclerosis, as well as tumors and gastrointestinal tracts resulting from post-resection anastomosis. It is also frequently used for dilated treatment of stenosis.
[0003]
Conventional dilatation balloon catheters used for dilatation of digestive tract stenosis are roughly classified into the following two types depending on the method of use. One is an over-the-wire type catheter in which the balloon of the catheter is placed in the stenosis along the guide wire, and the other is by directly pushing the catheter without using the guide wire. This is an on-the-wire catheter that places the balloon in the stenosis. The former catheter is used, for example, for expanding a stenosis of an intestinal tract or the like that is originally severely bent, or a stenosis that has occurred in a bent position due to an anastomosis after tumor resection, while the latter is relatively straight Used to dilate the stenosis of the digestive tract, such as the esophagus.
[0004]
In recent years, so-called endoscopic dilatation is frequently performed in which dilatation using a balloon catheter is performed while observing on a monitor using an endoscope (hereinafter referred to as direct viewing). In this case, the balloon catheter is inserted from the forceps opening 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 action. Observed that the stenosis or occlusion was released through the balloon under direct vision as a guideline for completing the expansion of the stenosis or occlusion by the balloon, and finally confirmed that the endoscope can pass through the stenosis or occlusion. Above, the surgeon determines that the expansion was successful. Thereafter, the balloon catheter is removed from the endoscope, the treatment site is observed under the endoscope, and after confirming that there is no problem such as abnormal bleeding, the treatment is completed.
[0005]
However, in conventional on-the-wire type balloon catheters as shown in Patent Document 1 and Patent Document 2, the re-deflated balloon after pressure expansion is bulky due to its structure and cannot be removed from the endoscope. There was a case. The structure is the tip of the tip with the balloon's distal joint and the base end of the shaft with the balloon's proximal joint, where the wire is fixed and the wire length in the balloon is always constant. It is the structure which becomes. On the other hand, as a balloon material for the dilatation balloon catheter, a polymer having a low compliance such as polyethylene terephthalate is generally selected. However, the balloon still expands in the axial direction when it is pressurized and expanded. Elongation at the time of pressure expansion of the balloon is suppressed by a wire having a certain length, and as a result, the balloon is retracted. Even when the balloon is deflated, the retracting of the balloon never disappears, and this portion becomes bulky and is caught at the exit of the forceps opening 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. It was a problem such as delayed response.
[0006]
[Patent Document 1]
Japanese Patent No. 2671196 [Patent Document 2]
Japanese National Patent Publication No. 10-513382 gazette [0007]
[Problems to be solved by the invention]
An object of the present invention is to provide an dilatation balloon catheter that can be reliably and safely removed from an endoscope after performing dilatation treatment of a stenosis or occlusion in a living body lumen such as a digestive tract.
[0008]
[Means for Solving the Problems]
That is, the present invention includes a shaft having at least one lumen penetrating in the lengthwise direction, a reinforcing body inserted through one lumen of the shaft, a balloon having a proximal joint at the distal end of the shaft, and A dilatation balloon catheter configured by a distal tip joined to a distal joint portion of a balloon and provided separately from the shaft, wherein the tip of the reinforcing body is a pressure inflation of the balloon in the lumen of the distal tip And at the time of re-contraction, the reinforcing body is movable back and forth in the axial direction of the reinforcing body, and the reinforcing body is fixed to the distal end portion of the shaft, and the distal tip is in the balloon. It is the dilatation balloon catheter characterized by extending to.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to examples. FIG. 1 schematically shows an on-the-wire dilatation balloon catheter according to an embodiment of the present invention. Further, FIG. 2 shows a cross-sectional view of the shaft of FIG.
FIG. 3 is a diagram showing a cross-section of the distal tip of the dilatation balloon catheter according to one embodiment of the present invention, and FIG. 4 is a diagram showing a cross-section of the distal tip of the dilatation balloon catheter according to another embodiment of the present invention. FIG. 5 is a cross-sectional view showing a state in which the reinforcement body using the metal tube of the dilatation balloon catheter according to still another embodiment of the present invention is fixed to the distal end portion of the shaft.
[0010]
In the on-the-wire dilatation balloon catheter of FIG. 1, the balloon (1) is hermetically joined at two parts on the shaft (2) and the tip (3). The shaft (2) has a single lumen (5) penetrating in the axial direction, and has a coaxial type structure in which the reinforcing body (4) is inserted into the lumen (5). The reinforcing body (4) is for improving the operability of the catheter alone without using a guide wire. The reinforcing body (4) extends from the lumen (5) of the shaft (2) inside the balloon (1) and is reinforced. 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 opened in the balloon (1), the inflation fluid can be sent into the balloon (1) through the lumen (5).
The structure of the catheter tube of the on-the-wire dilatation balloon catheter according to the present invention is not limited to the above. For example, it has a biaxial structure having two lumens, a main lumen and a sub-lumen. Also good. In this case, the reinforcing body can be inserted into one of the lumens, and at least another lumen can be opened in the balloon, whereby the inflation fluid can be sent 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) when dilating the stenosis or occlusion is generally the inner diameter of the living body lumen before stenosis or occlusion, but the inner diameter of the body lumen is less than 4 mm or more than 24 mm. There is almost no. The length of the cylindrical portion effective for expanding the balloon (1) is preferably 20 to 80 mm, more preferably 40 to 60 mm. If it is less than 20 mm, it is not preferable because it is difficult to place the balloon in the stenosis or occlusion, and there is almost no linear biological lumen exceeding 80 mm, which is not preferable from the viewpoint 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 contrast to the shaft (2), for example, bismuth oxide, A contrast-enhancing substance such as bismuth carbonate can also be combined.
The outer diameter of the shaft (2) has a thickness that allows for insertion into the forceps opening of the endoscope, a lumen (5) that allows the balloon inflation fluid to pass through without difficulty, and kink resistance. In order to keep, 1.5-3 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 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 be moved back and forth. Have Therefore, even when the balloon (1) extends in the axial direction at least during the pressure expansion, the balloon (1) is not retracted because the reinforcing body (4) does not suppress the length to a certain length. Therefore, unlike an expansion balloon catheter having a conventional structure, there is no bulkiness due to the retraction of the balloon (1) at the time of contraction. Can be removed from the endoscope.
[0014]
Furthermore, the tip (3) extends into the balloon. This is because the tip of the reinforcing body (4) contacts the inside of the balloon when the balloon (1) extends larger than the axial length of the reinforcing body (4) inserted into the balloon when the balloon (1) is pressurized and inflated. This is to prevent the balloon (1) from being damaged, and can 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) during pressure expansion. The axial length of the reinforcing body (4) located in the tip (3) is also increased. As a result, the axial length of the distal tip (3) becomes larger than necessary, and the catheter is inserted into the body. Since it becomes easy to catch and insertion property worsens, it is not preferable.
[0015]
The material of the tip (3) used for the on-the-wire dilatation balloon catheter according to the present invention preferably has a certain degree of flexibility and kink resistance, and examples thereof include nylon elastomer and polyurethane elastomer. . The tip shape of the tip (3) is preferably rounded to prevent perforation of the digestive tract. The shape of the end of the tip (3) that extends into the balloon is preferably chamfered or rounded to reduce the possibility of damage to the balloon (1). . Furthermore, you may taper the part extended in the balloon of a front-end | tip tip (3) in order to reduce bulkiness.
[0016]
Further, as shown in FIG. 4, the tip (3) has a tip tip (3) to improve the kink resistance and reduce the risk that the tip of the reinforcing body (4) protrudes from the tip tip (3). A reinforcing material (9) may be attached around the inner cavity (8). Examples of the reinforcing material (9) include a spring, a coil, and a metal mesh.
[0017]
The material of the reinforcing body (4) is preferably a metal from the viewpoint of pushability and cost, and more preferably stainless steel such as high-strength stainless steel for springs. For the purpose of improving kink resistance, for example, a superelastic metal such as nitinol (nickel-titanium alloy) may be used. Moreover, although a single wire is preferable as the reinforcing body (4), the present invention is not limited to this, and may be a twisted wire, for example. When the reinforcing body (4) is a twisted wire, it is possible to improve kink resistance without using a superelastic metal. Furthermore, the tip of the reinforcing body (4) is preferably rounded.
[0018]
For fixing the reinforcing body (4) to the distal end of the shaft (2), for example, a metal tube (10) is attached to the 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 metallic tube (10) is further reduced for the purpose of reducing the bulk of the proximal joint (6) of the balloon (1). The proximal joint (6) of the balloon (1) may be attached to the distal 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 dilation treatment of a narrowed or occluded portion of a living body lumen such as a digestive tract. is there.
[Brief description of the drawings]
FIG. 1 shows an outline of an on-the-wire dilatation balloon catheter according to an embodiment of the present invention.
FIG. 2 is a sectional view of a shaft of an on-the-wire dilatation balloon catheter according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of the distal tip of an on-the-wire dilatation balloon catheter according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view of a 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 reinforcement body of an on-the-wire type dilatation balloon catheter according to still another embodiment of the present invention is fixed to a distal end portion of a shaft.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Balloon 2 Shaft 3 Tip tip 4 Reinforcement body 5 Lumen 6 Proximal joint 7 Distal joint 8 Lumen 9 (of tip) Reinforcement material 10 Metal tube

Claims (1)

A shaft having at least one lumen penetrating longitudinally, a reinforcement inserted through one lumen of the shaft, a balloon having a proximal joint at a distal end of the shaft, and a distal joint of the balloon A dilatation balloon catheter that is joined to a portion and is provided separately from the shaft, and the tip of the reinforcing body is at the time of pressurization and re-contraction of the balloon in the lumen of the tip The reinforcing body is movable back and forth in the axial direction of the reinforcing body, and the reinforcing body is fixed to the distal end portion of the shaft, and the distal tip extends into the balloon. A dilatation balloon catheter characterized by comprising:

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