JPH1099449A - Therapeutical tool for tubular organ - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a therapeutical tool for tubular organ which gives a sufficient retaining force at the time of expansion without impairing flexibility in the axial direction and which can be smoothly drawn into a catheter at the time of collecting back. SOLUTION: A U-part 14 consisting of a bend 12 and a pair of arms 13 continued to the bend 12 is formed so that the bends 12 are oppbsingly positioned alternately to form a flat line as a whole to assume a spread shape being coupled zigzag and a therapeutical tool 11 for a tubular organ is formed by bending the arms 13 in the circumferential direction into a cylinder. In this spread shape, the line width stretching in the axial direction of the bends 12 is made smaller than the line width of the arms 13 in their part stretching in the circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treatment tool for a tubular organ which is inserted into a tubular organ of a human body such as a blood vessel, a ureter or the like, and which keeps the lumen of the tubular organ open.

[0002]

2. Description of the Related Art In the treatment of myocardial infarction and the like, for example, a treatment for preventing occlusion of a blood vessel is performed by inserting a dilator called a stent into a stenotic portion of the blood vessel. Also, in the treatment of ureteral stones and the like, a stent may be used to maintain the ureter in an expanded state in order to facilitate the discharge of stones.

[0003] Generally, a stent is mounted on the outer periphery of the distal end of a balloon catheter in a reduced diameter shape, inserted into an occluded diseased part through a guide catheter, and then inflated by forcing the balloon of the balloon catheter to expand to obstruct the occlusion. The tubular organ is expanded by placing it in the affected area.

[0004] In many cases, a stent is left in a tubular organ. However, a thrombus or atherosclerotic tissue may adhere to the inner periphery of the stent and cause restenosis. For this reason, when a stent is inserted for a temporary treatment, it is desired that the stent be promptly collected when there is no risk of obstruction of the tubular organ.

As an example of a conventional stent, Japanese Patent Laid-Open Publication No.
No. 18,1993 discloses a longitudinally flexible stent having a plurality of cylindrically shaped elements that are independently expandable in the radial direction and interconnected to be substantially aligned with a common axis. . As the radially expandable cylindrical element, for example, a cylindrical element that extends in a circumferential direction in a wavy shape and is connected in an annular shape is used.

Japanese Patent Publication No. 6-44910 discloses a snake shape including a series of straight portions and a plurality of bent portions, and the straight portions are joined by the bent portions to form a series of alternate loops. The snake-like configuration is formed into a cylindrical shape having a longitudinal axis, and the linear portion surrounds the axis and is bent into a substantially cylindrical shape substantially perpendicular to the axis. It has been disclosed.

[0007] Further, Japanese Patent Application Laid-Open No. 6-292730 discloses a stent in which a large number of slits are formed in a circumferential wall along the axial direction in a cylindrical wall as a whole so as to radially expand in a radial direction. I have.

Further, Japanese Patent Application Laid-Open No. 4-256759 discloses a stent made of a mesh made of a shape memory alloy or a weft-knitted cylindrical member, which can be expanded in diameter by a shape restoring force.

[0009]

However, in the stent disclosed in Japanese Patent Application Laid-Open No. 6-181993, since the linear portion and the curved portion of the cylindrical element have the same width, they are difficult to spread at the time of expansion and may be unevenly expanded. was there. In addition, when the stent is expanded and placed in a tubular organ, it is difficult to collect the stent through a catheter or the like.

In the stent disclosed in Japanese Patent Publication No. 6-44910, the holding force after expansion is weak, the diameter of the stent is reduced by the pressure of the inner wall of the blood vessel, and there is a risk of restenosis. In addition, since it is formed of a series of wires, it can be collected through a catheter or the like, but has a problem that it is difficult to smoothly pull it into the catheter at the time of collection because the bent portion does not easily extend linearly.

Further, the stent disclosed in Japanese Patent Application Laid-Open No. 6-292730 has a problem that thrombotic restenosis is likely to occur because the stent has many metal parts in an expanded state. In addition, when the stent is expanded and placed in the tubular organ, it is difficult to collect the stent through a catheter or the like.

Further, in the stent disclosed in Japanese Patent Application Laid-Open No. 4-256759, the total length before and after the expansion is large, and the stent must be selected in consideration of the length after the indwelling. There was a problem. It should be noted that a wire made of a series of wires, such as a flat knitted wire, can be collected through a catheter or the like, but has a problem that it is difficult to smoothly pull the wire into the catheter because there are many bent portions.

Accordingly, an object of the present invention is to provide a treatment for a tubular organ capable of obtaining a sufficient holding force at the time of expansion without impairing the flexibility in the axial direction and being able to be smoothly drawn into the catheter at the time of recovery. To provide tools.

[0014]

Means for Solving the Problems In order to achieve the above object, a first aspect of the present invention is that a U-shaped portion comprising a bent portion and a pair of arms connected to the bent portion is formed by the U-shaped portion. The parts are alternately reversed, and the main part is a flat line forming a developed shape connected in a zigzag shape as a whole, with the arms of the flat line facing the circumferential direction, and bending the flat line into a cylindrical shape. In the tubular organ treatment tool, the portion extending in the axial direction of the bent portion is narrower in line width than the portion extending in the circumferential direction of the arm portion. .

According to a second aspect of the present invention, in the first aspect, the arms extend in parallel with each other, and each of the arms has a bent portion at an intermediate portion extending from a bent portion at one end to a bent portion at the other end. It has a portion bent in a crank shape so as to separate the portions, and each of the bent portions, in the reduced diameter state, enters the space between the bent portion and the bent portion located on the opposite side in the circumferential direction, In the expanded state, it is a treatment tool for a tubular organ that is moved away from the space.

A third aspect of the present invention is that, in the second aspect, a portion extending in the axial direction of the crank-shaped portion has a smaller line width than a portion extending in the circumferential direction of the arm portion. Is a treatment device for tubular organs.

According to the first aspect of the present invention, the portion extending in the axial direction of the bent portion has a smaller line width than the portion extending in the circumferential direction of the arm portion, so that flexibility in the axial direction is not impaired. In addition, it is possible to obtain a sufficient holding force at the time of expansion by increasing the area of the arm that contacts the inner wall of the tubular organ. In addition, when attempting to recover after being placed in the tubular organ, the bent portion having the reduced line width is easily stretched straight, so that it can be smoothly drawn into the catheter.

According to the second aspect of the present invention, each bent portion enters the space between the bent portions located on the opposite side in the circumferential direction in the reduced diameter state, and enters the space in the expanded diameter state. Since the arm is moved away from the arm, the arrangement density of the arms can be increased, and the holding force at the time of expansion can be increased. Also, since the arms are perpendicular to each other in the axial direction and parallel to each other, when expanding, they will slide on the same place on the inner wall of the tubular organ,
Less likely to damage the inner wall of the tubular organ.

According to the third aspect of the present invention, not only the bent portion, but also the portion extending in the axial direction of the crank-shaped portion,
By reducing the line width, the flexibility in the axial direction is further improved, and the line is more likely to be linear when pulled into the catheter during collection.

[0020]

1 to 4 show one embodiment of a treatment device for a tubular organ according to the present invention. 1 is a perspective view showing a state where the diameter is increased, FIG. 2 is a perspective view showing a state where the diameter is reduced, FIG. 3 is a development view, and FIG. 4 is a perspective view showing a state where the diameter is increased at the time of collection.

As shown in FIG. 3, the treatment device 11 for a tubular organ is made of, for example, stainless steel, tantalum, titanium, platinum,
It consists of a single continuous flat wire made of gold, tungsten, shape memory alloy, or the like. And, in the unfolded shape, it has a plurality of U-shaped portions 14 each including a bent portion 12 and a pair of arms 13 connected to the bent portion 12. Further, the U-shaped portion 14 has a bent shape in which the bent portions 12 are alternately reversed, and is connected in a zigzag shape as a whole.

In this embodiment, an intermediate portion of the arm portion 13 forms a bent portion 15 which is bent in a crank shape so that the bent portions 12 are separated from each other. The straight portions of the arms 13 are parallel to each other. This arm 13
Is formed into a cylindrical shape toward the circumferential direction, thereby forming a treatment tool 11 for a tubular organ.

[0023] The features of the present invention are as follows.
Portions along the axial direction, ie, bent portion 12, bent portion 15
Have a line width a, b along the circumferential direction, that is, the arm 1
3 is narrower than the line width c of the straight portion.
Specifically, the line widths a and b of the bent portion 12 and the bent portion 15 are:
Preferably 0.5-2.0 mm, most preferably 0.8
mm, and the line width c of the arm 13 is preferably 1.0 to
It is 3.0 mm, most preferably 2.0 mm. The width d in the circumferential direction in the developed shape is preferably 2 to 2.
It is 30 mm, most preferably 10 mm. Further, the total length e in the axial direction is preferably 5 to 70 mm, most preferably 30 mm. The thickness of the flat wire is preferably 50 to 150 μm, and most preferably 80 μm.

By setting the width of the flat line, the thickness of the flat line, the width in the circumferential direction of the developed shape, the length in the axial direction, and the like as described above, a stent that is particularly preferable as a stent for expanding a stenotic portion of a blood vessel is obtained. Can be provided.

As shown in FIGS. 1 and 2, when the developed shape shown in FIG. 3 is curved into a cylindrical shape, the bent portion 12 enters the space between the bent portions 12 facing each other in the circumferential direction. . Then, in the reduced diameter state shown in FIG. 2, the bent portion 12 is inserted deeply into the space between the opposed bent portions 12, and FIG.
In the diameter-expanded state shown in (1), the bent portion 12 moves away from the space between the opposed bent portions 12. With such a shape, the arrangement density of the arms 13 is increased,
The retention force when the tubular organ is expanded can be increased.

The surface of the flat line constituting the treatment tool 11 for a tubular organ is coated with a polyfluoroethylene resin, a heparin-containing resin, a hydrophilic resin or the like in order to prevent thrombus from adhering. Is preferred.

Next, a method of using the treatment device 11 for a tubular organ will be described as an example applied to a stenotic part of a blood vessel.

First, a guide catheter is percutaneously inserted into a blood vessel by the well-known Seldinger method, and its distal end is made to reach the vicinity of the stenosis. Then, the treatment tool 11 is mounted in a reduced diameter state on the outer periphery of the balloon at the distal end of the balloon catheter, and the balloon catheter is guided into the blood vessel through the guide catheter.

Further, using the guide wire inserted into the balloon catheter as a guide, the balloon catheter is further pushed forward, and the treatment tool 11 attached to the distal end is placed in the stenosis. In this state, a liquid such as saline is injected into the balloon through the balloon catheter, and the balloon is inflated to expand the treatment tool 11.

Thereafter, the liquid in the balloon is extracted, the balloon is deflated, the balloon catheter is extracted from the inner periphery of the treatment tool 11, and the treatment tool 11 is placed. Thus,
The therapeutic device 11 can prevent or treat myocardial infarction or cerebral infarction by expanding a stenotic portion of a blood vessel.

In the treatment device 11 of the present invention, the line width of the arm 13 extending in the circumferential direction is widened, and the arrangement density of the arm 13 in the axial direction is high. In addition, the stenotic portion of the blood vessel can be reliably expanded. Further, since the line width of the bent portion 12 and the bent portion 15 along the axial direction is narrowed, flexibility in the axial direction is sufficiently maintained, and insertion into the catheter can be easily performed.

When the stenosis of the blood vessel is healed and the treatment tool 11 is no longer needed, a catheter is inserted and its distal end is brought close to the treatment tool 11, and the end of the treatment tool 11 is clamped by forceps or the like. Can be grasped and pulled into the catheter for collection. FIG. 4 shows the recovered state, in which the line width of the bent portion 12 and the bent portion 15 is narrowed, so that the bent portion 12 is easily bent and straightened at that portion, and is easily drawn into the catheter. be able to.

Further, the treatment tool 11 is provided in Japanese Patent Publication No. 6-44.
As compared with the stent shown in No. 910, the following excellent effects are obtained.

FIG. 9A shows the movement of the U-shaped portion 14 when the diameter of the treatment tool 11 of the above embodiment is increased.
FIG. 2B shows the movement of the U-shaped portion 24 when the diameter of the stent 21 shown in Japanese Patent Publication No. 6-44910 is expanded. In the treatment device 11 of the above embodiment, even if the U-shaped portion 14 moves while expanding in diameter, the arm portion 13 only moves so as to rub the same position, so that the inner wall of the blood vessel is less damaged. On the other hand, in the stent 21 of Japanese Patent Publication No. Hei 6-44910, when the U-shaped portion 24 moves, as shown by an imaginary line in the figure,
Since not only the bent portion 22 but also the arm portion 23 are displaced, the inner wall of the blood vessel is easily peeled off.

FIG. 5 shows another embodiment of the treatment device for a tubular organ according to the present invention. In the following embodiments, substantially the same parts as those in the embodiment of FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted.

The treatment device 31 for a tubular organ of this embodiment has basically the same structure as the treatment device 11 of the embodiment shown in FIGS. If the line width is
The difference is that the line width of the arm portion 13 is the same as the line width. As a result, when the treatment tool 11 is collected, the bent portion 15 does not easily extend linearly. However, since the bent portion 15 is closer to a linear shape than the bent portion 12, it is not so easy to draw the catheter into the catheter. There is no problem. Therefore, even with the treatment tool 31 having such a developed shape, the object of the present invention can be achieved.

FIG. 6 shows still another embodiment of the treatment device for a tubular organ according to the present invention. In the treatment tool 41 for a tubular organ of this embodiment, a linear arm 43 having no bent portion is connected between the bent portions 12. The arms 43 are slightly inclined to spread outward with respect to each bend 12, so that when bent into a cylindrical shape, the bend 12
However, it enters into the space between the bent portions 12 facing each other in the circumferential direction. The line width of the bent portion 12 along the axial direction is smaller than the line width of the arm 43.

Also in this treatment tool 41, the flexibility in the axial direction can be improved by reducing the line width of the bent portion 12, and the line width of the arm 43 can be increased by expanding the line width of the arm 43. Can be improved. Further, since the line width of the bent portion 12 is narrow, it is easy to extend linearly at the time of collection, and it can be smoothly drawn into the catheter. However, in this treatment tool 41, FIG.
The operation and effect shown in (a) cannot be obtained.

FIGS. 7 and 8 show still another embodiment of the treatment device for a tubular organ according to the present invention. FIG. 7 is a perspective view of a main part, and FIG. 8 is a sectional view of a connection part. As shown in FIG. 7, the treatment tool 51 for a tubular organ includes an expansion member 52 and a linear member 53 connected to one end 52a. The expansion member 52 has the same shape as the treatment tool 11 of the embodiment shown in FIGS. 1 to 4, and differs only in that one end 52 a is drawn out at a predetermined length in the axial direction. I have.

A connecting portion 54 connecting one end 52a of the expanding member 52 and one end 53a of the linear member 53.
Has the following configuration. That is, the end 53a of the linear member 53 is gradually reduced in diameter so as to have the same thickness and preferably the same cross-sectional shape as the end 52a of the expansion member 52, and a platinum wire (or (A platinum alloy wire) 55 is wound. Then, the linear member 53
In the vicinity of the butted end of the end 53a of the expansion member 52 and the end 52a of the expansion member 52, the silver solder 56a is fixed so as to melt and fill the gap. Further, silver brass 56b and 56c are also fixed to both ends of the platinum wire 55, and these portions are formed into a smoothly tapered shape to prevent the portions from being caught by a catheter or the like at the time of insertion into or removal from the tubular organ. Contributes to prevention. In addition, the platinum wire 55 not only connects the linear member 53 and the expansion member 52 but also functions as a contrast coil for confirming the position with an X-ray when the expansion member 52 is sent to the affected part of the tubular organ. I do.

In this treatment tool 51, since the linear member 53 is connected to the expansion member 52, the part of the expansion member 52 is mounted on a balloon catheter or the like and inserted into the tubular organ, and the same method as described above is used. After being expanded and arranged, the linear member 53
Is left in the body while connected. Then, at the time of collection, after the catheter is inserted into the outer periphery of the linear member 53, the extension member 52 can be pulled into the catheter only by pulling the linear member 53. Therefore, when a coronary artery dilatation operation (PCTA) is performed using a balloon catheter or the like, it is inserted to prevent occlusion due to contraction (closure phenomenon), which is likely to occur within 24 hours after the operation. It is suitable as a stent or the like which is taken out when there is no danger of obstruction.

[0042]

As described above, according to the present invention,
Since the line extending in the axial direction of the bent portion is narrower than the line extending in the circumferential direction of the arm, the area of the arm which abuts on the inner wall of the tubular organ without impairing the flexibility in the axial direction. And a sufficient holding force at the time of expansion can be obtained. In addition, when attempting to recover after being placed in the tubular organ, the bent portion having the reduced line width is easily stretched straight, so that it can be smoothly drawn into the catheter.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tubular organ treatment tool according to an embodiment of the present invention in an expanded state.

FIG. 2 is a perspective view of the treatment tool in a reduced diameter state.

FIG. 3 is a development view of the treatment tool.

FIG. 4 is a perspective view showing a state in which the treatment tool is stretched from an end when being collected.

FIG. 5 is a development view showing another embodiment of the treatment device for a tubular organ of the present invention.

FIG. 6 is a development view showing still another embodiment of the treatment device for a tubular organ of the present invention.

FIG. 7 is a perspective view of an essential part showing still another embodiment of the treatment device for a tubular organ of the present invention.

FIG. 8 is a cross-sectional view of a connecting portion of the treatment tool for the tubular organ.

FIG. 9 shows a tubular organ treatment device according to an embodiment of the present invention;
It is explanatory drawing which shows the movement at the time of diameter expansion with the conventional stent.

[Explanation of symbols]

 11, 31, 41, 51 Treatment device for tubular organ 12 Bending part 13, 43 Arm part 14 U-shaped part 15, 35 Bending part 52 Expansion part 53 Linear part 54 Connection part 55 Platinum wire 56a, 56b, 56c Low Lumber

Claims (3)

[Claims] A flat U-shaped portion comprising a bent portion and a pair of arms connected to the bent portion, wherein the bent portion is alternately reversed to form a developed shape which is connected in a zigzag shape as a whole. Mainly a wire, the arm of the flat wire is oriented in the circumferential direction, and in a treatment tool for a tubular organ configured by bending the flat wire into a cylindrical shape, a portion extending in the axial direction of the bent portion,
A treatment device for a tubular organ, wherein a line width is narrower than a portion extending in a circumferential direction of the arm portion. 2. The arms extend parallel to each other,
At an intermediate portion from the bent portion at one end to the bent portion at the other end, the intermediate portion has a portion bent in a crank shape so as to separate the bent portions, and each bent portion is, in a reduced diameter state, a circumferential direction. 2. The therapeutic device for a tubular organ according to claim 1, wherein the treatment device enters a space between the bent portions located on the opposite side of the bent portion and moves away from the space in the expanded state. 3. The treatment device for a tubular organ according to claim 2, wherein a portion extending in the axial direction of the crank-shaped portion has a smaller line width than a portion extending in the circumferential direction of the arm portion.