JP5398971B2 - Stent placement device - Google Patents

Description

  The present invention relates to a stent indwelling device for indwelling a stent used for expanding the diameter of a stenosis occurring in, for example, the esophagus.

Conventionally, as a stent placement device for placing a stent in the body, as shown in FIG. 19, an outer tube 101 and an inner tube 102 are provided, and a stent 103 is interposed between the two tubes, and the stent 103 is placed inside. There is one that is inserted into the body using a channel of an endoscope and placed at a predetermined position (for example, Patent Document 1).
JP 2002-291765 Gazette

By the way, in the technique described in the said patent document 1, the following problems were left.
For example, when the stent 103 is placed in the narrowed portion Sa of the esophagus S, first, the distal end locking portion 104 attached to the distal end of the inner tube 102 is locked to the distal end opening 101a of the outer tube 101 as shown in FIG. Then, the narrowed portion Sa is inserted into the narrowed portion Sa using a reduced diameter portion 104a which is provided at the distal end of the distal end locking portion 104 and gradually decreases toward the distal end side. Next, as shown in FIG. 20, an operation unit (not shown) on the hand side is operated, and the outer tube 101 is pulled back to the proximal end side to expose the stent 103. Thereafter, the inner tube 102 is pulled back to the proximal end side, and the stent 103 is placed in the stenosis part Sa.

When the inner tube 102 is pulled back to the proximal end side, as shown in FIG. 21, the distal end locking portion 104 is caught by the distal end of the stent 103 and moved together with the stent 103 toward the proximal end side. In this case, the stent 103 is displaced from the position to be placed, and in the worst case, after the displaced stent 103 is removed, it is necessary to place the stent again from the beginning.
As described above, the technique described in Patent Document 1 has a problem that the indwelling operation is very troublesome.
Further, a step 105 is formed at the engaging portion between the distal end locking portion 104 attached to the distal end of the inner tube 102 and the distal end opening 101a of the outer tube 101 (see FIG. 9), and between the outer tube 101 and the inner tube 102. When the stent 103 is interposed and sent to the stenosis part Sa, there is a problem that the step 105 is caught by the stenosis part Sa.

  The present invention has been made in view of the above circumstances, and its purpose is to prevent the stent from being displaced when the inner tube is pulled back to the proximal end side. It is an object of the present invention to provide a stent indwelling device that can be easily inserted into a stenosis without causing a step between a member attached to the distal end and the distal end opening of the outer tube.

The present invention employs the following means in order to solve the above problems.
A stent indwelling device according to the present invention is a stent indwelling device for indwelling a cylindrical stent in a body, and is disposed at an outer tube, an inner inserted through the outer tube, and a tip of the inner. A diameter reduction mechanism, wherein the stent is interposed between the outer tube and the inner, and the diameter reduction mechanism is interposed between the outer tube and the inner. A large diameter state that is larger than the outer diameter of the stent in the formed state, and a small diameter that is smaller than the inner diameter of the stent that is not expanded when the stent is exposed from the outer tube into the body. The outer diameter can be changed between the states, and the diameter-reducing mechanism in the large-diameter state is in contact with the distal end opening of the outer tube, thereby The outer surface of the outer tube and the outer surface of the diameter reducing mechanism are continuous at the contact portion between the tip opening and the diameter reducing mechanism, and the outer surface of the diameter reducing mechanism is continuous toward the tip from the locking portion with respect to the tip opening. It has a shape that gradually becomes thinner .

According to this stent indwelling device, since the diameter-reducing mechanism capable of reducing the diameter is arranged at the distal end of the inner, the diameter-reducing mechanism is set when the inner is pulled back to the proximal side after setting the stent to the normal position. By reducing the diameter, it is possible to avoid the inner tip from being caught by the stent tip. As a result, when the inner is pulled back to the proximal end side, the stent can be prevented from moving together with the inner and being displaced from the normal position.
In addition, since the diameter reducing mechanism is locked to the distal end opening of the outer tube so that the outer peripheral surfaces of the outer tube are smoothly continuous without unevenness at the contact portion between the distal end opening of the outer tube and the diameter reducing mechanism. The diameter reducing mechanism is reduced in diameter so that there is no step between the outer opening of the outer tube and the outer diameter of the outer diameter reducing mechanism, and gradually becomes thinner from the engaging portion with the outer tube toward the tip. Therefore, it becomes easy to insert the outer tube in which the stent is incorporated into the narrowed part of the body.

In the stent indwelling device according to the present invention, it is preferable that the diameter reducing mechanism is constituted by a deflatable balloon.
In this case, since a balloon with a proven track record is used as a medical treatment instrument, it is excellent in reliability, and the expansion / contraction operation is easy by taking in and out a fluid such as air, so that handling is also easy.

Further, in the stent placement device according to the present invention, it is preferable that a stepped portion is formed at a portion of the outer periphery of the balloon that is engaged with the distal end opening of the outer tube.
In this case, the step formed on the outer periphery of the balloon is appropriately sized, and this step is abutted with the step of the tip opening of the outer tube so that the contact between the tip opening of the outer tube and the balloon It is possible to easily realize a configuration in which the outer peripheral surfaces of each other are smoothly continuous without having irregularities.

In the stent placement device according to the present invention, it is preferable that the balloon is formed in a hook shape.
In this case, when the balloon is inserted into the stenosis, there is no corner on the outer peripheral portion of the balloon, so that the stent can be inserted without damaging the stenosis.

In the stent placement device according to the present invention, it is preferable that the balloon is formed in a rhombus shape in a side view.
In this case, the stenosis can be quickly expanded by the diamond-shaped balloon, and this is advantageous particularly when the stenosis is narrow.

In the stent placement device according to the present invention, it is preferable that the balloon is formed in a rhombus shape in a side view.
In this case, the stenosis can be quickly expanded by the diamond-shaped balloon, and this is advantageous particularly when the stenosis is narrow.
In the stent indwelling device according to the present invention, it is preferable that the balloon is disposed on the distal end side of the inner stent insertion position.
In this case, since the balloon is arranged on the tip side from the stent insertion position, the balloon can quickly spread the stenosis portion as the stent placement portion, and the balloon is placed after the stent is placed in the stenosis portion. Can be pulled out to the base end side together with the inner.

  According to the present invention, the stent is not displaced when the inner tube is pulled back to the proximal end side, and the stent can be placed easily. Further, there is no step between the member attached to the distal end of the inner tube and the distal end opening of the outer tube, and insertion into the constricted portion is facilitated.

Hereinafter, each embodiment according to the present invention will be described with reference to the drawings.
[First Embodiment]
1 to 7 show a first embodiment of a stent placement device according to the present invention, FIG. 1 is a cross-sectional view of a main part, and FIG. 2 is an enlarged cross-sectional view showing a relationship between a balloon and an outer tube.

  In the figure, reference numeral 1 denotes an outer tube, and 2 denotes an inner tube inserted inside the outer tube. These tubes are made of a material that is harmless to the human body and has an appropriate flexibility, such as a fluorine-based, nylon-based, or silicon-based resin. A stent 3 is interposed between the two tubes, and the stent 3 is inserted into the body through a channel of an endoscope (not shown) in this state. Here, the diameter of the stent 3 is set smaller than the diameter of the outer tube 1. When the stent 3 itself is made of a stretchable material, the diameter of the stent 3 may be set larger than the diameter of the outer tube 1. In this case, the stent 3 is set in the outer tube 1 in a contracted state.

A guide wire 4 is inserted into the inner tube 2, and the tip of the guide wire 4 is previously placed at a predetermined location in the body. A stopper 5 is attached to a predetermined position of the inner tube 2. The stopper 5 abuts on the rear end portion 3a of the stent 3 and restricts the movement of the stent 3 toward the base end side (right side in FIG. 1).
In this specification, the distal end side of the outer tube 1 and the inner tube 2 refers to the left side of FIG. 1, and the proximal end side refers to the right side of FIG.

  Further, a hook-shaped balloon 6 is attached to the distal end side of the location where the stopper 5 of the inner tube 2 is attached. The balloon 6 constitutes a diameter reducing mechanism 9 capable of reducing the diameter. The balloon 6 is made of a material that can be deformed by contraction. For example, if the shell itself is made of a material that can shrink itself, such as latex or silicone, and the shell part that forms the outer shape when the air inside is pulled out, it does not shrink itself, such as pet or nylon. Sometimes it is made of a material that shrinks and deforms to fold. 1 and 2 show a state where air is injected into the internal space of the balloon 6, and FIGS. 6 and 7 show a state where air is extracted from the inside.

  As shown in FIG. 2, a stepped portion 7 is formed at a location on the outer periphery of the balloon 6 in a state where air is injected therein and slightly shifted to the proximal end side from the maximum diameter. The stepped portion 7 is locked to the stepped portion 1a at the distal end opening of the outer tube 1, so that the outer peripheral surface of the balloon 6 and the distal end opening of the outer tube 1 is smooth without any unevenness. It will be continuous.

  As a specific method for forming the step portion 7, for example, when the balloon 6 is made of a material that can contract itself, such as latex or silicon, the step portion 7 is formed as shown in FIG. It is conceivable to vary the thickness of the part to be performed. Further, when the balloon is made of a material that does not contract itself such as pet or nylon, as shown in FIG. 4, it may be possible to form the stepped portion 7 in advance at a required portion of the outer surface during molding.

In the former case, the outer surface is flush when air is not injected into the interior, but when air is injected into the interior, the difference in the amount of expansion occurs when the thickness is changed. As shown in a two-dot chain line in FIG. 3, a stepped portion 7 is formed on the outer surface of the portion having a different thickness.
In the latter case, since the step portion 7 is formed in a required portion in advance, the step portion 7 remains formed on the outer surface not only when air is injected but also when the air is removed. .

Further, in the balloon 6 into which air is injected, a reduced diameter portion 8 is formed on the distal end side of the step portion 7 that is a locking portion with the outer tube 1 so that the diameter gradually decreases toward the distal end. Has been.
Note that the fluid for expanding the diameter of the balloon 6 is not necessarily limited to air, and may be, for example, a solution containing saline or a contrast medium.

Next, the case where the stent 3 is set in the stenosis part Sa of the esophagus S using the stent indwelling device having the above configuration will be described.
First, as shown in FIG. 1, the stent 3 is inserted and set between the outer tube 1 and the inner tube 2.
That is, the rear end portion 3a of the stent 3 is abutted against the stopper 5, and the outer tube 1 is placed on the outside thereof. Thereafter, air is sent into the balloon 3 through an air pipe (not shown) to inflate the balloon 3. At this time, the stepped portion 7 of the balloon 3 is locked to the stepped portion 1 a of the distal end opening of the outer tube 1.

  The stent indwelling device having the stent 3 set therein is inserted into, for example, an endoscope channel, orally introduced, and guided to the esophagus S while being observed with the endoscope. Then, the stenosis portion Sa of the esophagus S is confirmed by an endoscopic image, and the stent placement device is guided by the guide wire 4 so that the stent 1 reaches a portion facing the stenosis portion Sa as shown in FIG. Move while.

  At this time, since the step portion 7 of the balloon 6 is locked to the step portion 1 a of the distal end opening of the outer tube 1, the outer peripheral surfaces of the outer tube 1 are uneven at the contact portion between the distal end opening of the outer tube 1 and the balloon 6. Therefore, there is no step between the opening of the outer tube 1 and the balloon 6. In addition, since the balloon 6 is provided with a reduced diameter portion 8 that gradually decreases in diameter from the locking portion with the outer tube toward the tip, the narrowed portion Sa of the outer tube 1 in which the stent 3 is set therein. Easy to insert into.

  Next, while confirming with an endoscopic image, the outer tube 1 is pulled back to the proximal end side in an operation section (not shown), and the stent 3 is exposed as shown in FIG. Next, the entire balloon 6 is reduced in diameter by extracting air from the inside, the maximum diameter of the balloon 6 is made smaller than the inner diameter of the stent 3, and a clearance is generated between the balloon 6 and the stent 3.

Thereafter, as shown in FIG. 7, the inner tube 2 is pulled back to the proximal end side, and the stent 3 is placed in the stenosis part Sa.
At this time, the diameter of the entire balloon 6 is reduced in advance by removing air from the inside, and a clearance is generated between the balloon 6 and the stent 3, so that the balloon 6 can be prevented from being caught by the distal end of the stent. As a result, when the inner tube 2 is pulled back to the proximal end side, the stent 3 can be prevented from moving together with the inner tube 2 and being displaced from the normal position.

[Second Embodiment]
FIG. 8 is a partial cross-sectional side view showing a second embodiment of the stent placement device according to the present invention. Note that, in the second to seventh embodiments described below, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The stent indwelling device according to the second embodiment is different from the stent indwelling device according to the first embodiment described above in that a balloon having a different shape is used.

That is, the cage-shaped balloon 6 is used in the stent indwelling device of the first embodiment, but the balloon 11 having a rhombus shape in side view is used in place of the stent indwelling device of the second embodiment. By using the balloon 11 having a rhombus shape when viewed from the side as described above, the stenosis part Sa can be pushed and spread quickly, and an advantage that the insertion into the stenosis part Sa is facilitated can be obtained.
Also in this case, a stepped portion 7 is formed at a predetermined position on the outer periphery of the balloon.

[Third Embodiment]
9 and 10 show a third embodiment of the stent placement device according to the present invention, FIG. 9 is a cross-sectional view of the main part, and FIG. 10 is a cross-sectional view showing the operation.
A characteristic part of the stent placement device of the third embodiment is that the diameter of the stent 3 projected from the outer tube 1 is expanded by the balloon 21.

  That is, the balloon 21 is composed of a conical portion 22 at the tip and a cylindrical portion 23 that extends rearward therefrom and whose length is set longer than the length of the stent 3. And this balloon 21 is expanded and contracted in three stages. The first stage is the most contracted state as shown by a two-dot chain line in FIG. 9, and the second stage is expanded at the tip end as shown by a solid line in FIG. In this state, the stent 3 is fitted to the outside of the cylindrical portion 23, and the third stage is a state in which the diameter is expanded to the maximum as shown in FIG. Is a state in which the diameter has been increased to a larger diameter.

According to this stent placement device, as shown in FIG. 9, the stent 3 is set in the overtube in a state in which the stent 3 is fitted to the outer surface of the cylindrical portion 23 of the balloon 21. In this state, the stent 3 is guided to, for example, a narrowed portion of the esophagus through the endoscope channel. And in the stage which reached this constriction part, the outer tube 1 is pulled back to the base end side, and as shown in FIG. 10, the stent 3 is exposed. Next, for example, air is sent into the balloon 21 via the inner tube 2 to expand the balloon 21 to the maximum diameter. Thereby, the diameter of the stent 3 can be expanded as compared with the state set in the outer tube 1.
Subsequently, after removing air from the balloon 21 and reducing the diameter as indicated by a two-dot chain line in FIG. 9, the stent 3 can be placed in the stenosis by pulling back the inner tube 2 together with the proximal end side.

  According to the stent placement device of the third embodiment, the diameter of the stent 3 exposed from the outer tube 1 can be expanded by the balloon 21, and the inner diameter of the outer tube 1 is not limited and is larger than that. The diameter stent 3 can be placed in the stenosis.

[Fourth Embodiment]
11 and 12 show a fourth embodiment of the stent placement device according to the present invention, FIG. 11 is a perspective view of the main part, and FIG. 12 is a perspective view showing the operation.
The characteristic part of the stent placement device of the fourth embodiment is that a diameter reducing mechanism 9 capable of reducing the diameter is provided in the inner tube 31 itself.

  That is, the diameter reducing mechanism 9 of this embodiment is provided with a plurality of (for example, four) cuts 32 extending in the circumferential direction at equal intervals on the outer circumference of the inner tube 31 made of an elastic material, Further, the pull wire 33 is connected to the tip of the inner tube 31. In the diameter reducing mechanism 9, when the pull wire 33 is pulled toward the front side, as shown in FIG. 12, the portion 34 with the cut 32 is expanded outward to expand the diameter, and the maximum diameter portion 11 is locked to the opening of the distal end of the outer tube (not shown), and when the pulling force on the pull wire 33 is released, the portion 34 in which the cut 32 is made has its original shape as shown in FIG. To come back.

According to the stent placement device of the fourth embodiment, the diameter reducing mechanism 9 has a very simple configuration including the inner tube 31 and the pull wire 33, so that cost reduction and ease of assembly can be achieved.
In the fourth embodiment, if necessary, a wire tension maintaining unit that maintains a state in which the pull wire is pulled to the near side may be provided on the proximal end side of the pull wire 33.

[Fifth Embodiment]
13 and 14 show a fifth embodiment of the stent placement device according to the present invention, FIG. 13 is a perspective view of the main part, and FIG. 12 is a perspective view showing the operation.
A characteristic part of the stent placement device of the fifth embodiment is that a diameter-reducing mechanism 9 provided at the tip of the inner tube 2 is configured by a water-soluble tip 41.

  That is, the diameter-reducing mechanism 9 of this embodiment is configured, for example, by attaching a tip 41 composed of two cones 41a and 41b whose bottom surfaces are aligned to the tip of the intertube 2. The chip 41 is made of a water-soluble material that is harmless to the human body, such as polyethylene glycol, polylactic acid, or polyglutamic acid. The large diameter portion of the tip 41 is locked so as to be continuous with a distal end opening of an outer tube (not shown).

  According to the stent indwelling device of the fifth embodiment, the tip 41 is engaged with the distal end opening of the outer tube in the form of a double cone before melting, as shown in FIG. After the exposure, the tip 41 is melted away by body fluid or the like as shown in FIG. Therefore, the distal end of the inner tube 2 can be pulled back to the proximal end side without being locked to the outer tube, and thereby, the stent 3 existing outside the inner tube 2 can be placed in the stenosis portion. .

[Sixth Embodiment]
15 and 16 show a sixth embodiment of the stent placement device according to the present invention, FIG. 15 is a perspective view of the main part, and FIG. 16 is a perspective view showing the operation.
The characteristic part of the stent placement device of the sixth embodiment is that the diameter-reducing mechanism 9 provided at the distal end of the inner tube 2 is constituted by a tip 51 that is detachably attached to the distal end of the inner tube 2. is there.

  That is, the diameter-reducing mechanism 9 of this embodiment is constituted by a tip 51 made of a material harmless to the human body such as silicone or fitted to the tip of the inner tube 2 by friction. The tip 51 is normally friction-fitted to the tip of the inner tube 2. When the tip 51 is forcibly protruded by the outer tube 1, the tip 51 comes out of the inner tube 2 and falls off. Accordingly, the distal end portion of the inner tube 2 can be pulled back to the proximal side while the stent 3 disposed on the proximal end side of the tip 51 is left in the body.

  In the sixth embodiment, the tip 51 is protruded forward by the outer tube 1 and detached from the inner tube 2. However, the present invention is not limited to this, and the tip 51 is disposed between the outer tube 1 and the inner tube 2. The tip 51 may be protruded away from the inner tube 2 by a middle tube (not shown).

[Seventh Embodiment]
17 and 18 show a seventh embodiment of the stent placement device according to the present invention, FIG. 17 is a perspective view of the main part, and FIG. 18 is a perspective view showing the operation.
A characteristic part of the stent placement device of the seventh embodiment is that a diameter-reducing mechanism 9 provided at the distal end of the inner tube 2 is attached to a distal end of the inner tube 2, and a tip 61 is attached to the proximal end of the tip 61. This is a point constituted by a balloon 62 extending to the side.

That is, in the diameter reducing mechanism 9 of this embodiment, a tip 61 having a diameter smaller than the inner diameter of the outer tube 1 is attached to the distal end of the inner tube 2, and the balloon 62 is connected to the tip end side of the tip 61 so as to be continuous with this tip. Is attached. That is, the diameter reducing mechanism 9 of this embodiment is a combined type of the tip 61 and the balloon 62.
In the seventh embodiment, since the relatively hard tip 61 is attached to the tip of the inner tube 2, when pushing the tip of the inner tube 2 into the narrowed portion, the tip is not crushed, and the pressure is smooth and small. You can push on.

The present invention is not limited to the above-described embodiment, and can be appropriately changed in design without departing from the spirit of the invention.
For example, in each of the above embodiments, the inner tube 2 is used inside the outer tube 1 as a member for guiding the stent 3. However, the inner member is not necessarily a tube, and may be a wire or a rod-like member. There may be.
For example, in each of the above-described embodiments, the case where the stent indwelling device in which the stent 3 is set is inserted into the body by using the endoscope channel has been described as an example. However, the present invention is limited to this. Alternatively, it may be inserted into the body using an overtube covering the insertion portion of the endoscope.

  Further, in each of the above embodiments, the case where the stent 3 is placed in the stenosis of the esophagus has been described as an example. However, the present invention is not limited thereto, and when the stent 3 is placed in other parts of the body, The present invention can be used.

It is sectional drawing of the stent placement apparatus of the 1st Embodiment of this invention. It is a partial expanded sectional view of the stent indwelling device. It is sectional drawing which shows an example in the case of forming a step part in a balloon. It is sectional drawing which shows the other example in the case of forming a step part in a balloon. It is sectional drawing which shows the process of indwelling a stent in a body using the stent indwelling apparatus of the 1st Embodiment of this invention. It is sectional drawing which shows the process of indwelling a stent in a body using the stent indwelling apparatus of the 1st Embodiment of this invention. It is sectional drawing which shows the process of indwelling a stent in a body using the stent indwelling apparatus of the 1st Embodiment of this invention. It is sectional drawing of the stent placement apparatus of the 2nd Embodiment of this invention. It is sectional drawing of the stent placement apparatus of the 3rd Embodiment of this invention. It is sectional drawing which shows the effect | action of the stent placement apparatus of the 3rd Embodiment of this invention. It is sectional drawing of the stent placement apparatus of the 4th Embodiment of this invention. It is sectional drawing which shows the effect | action of the stent placement apparatus of the 4th Embodiment of this invention. It is sectional drawing of the stent placement apparatus of the 5th Embodiment of this invention. It is sectional drawing which shows the effect | action of the stent placement apparatus of the 5th Embodiment of this invention. It is sectional drawing of the stent placement apparatus of the 6th Embodiment of this invention. It is sectional drawing which shows the effect | action of the stent placement apparatus of the 6th Embodiment of this invention. It is sectional drawing of the stent placement apparatus of the 7th Embodiment of this invention. It is sectional drawing which shows the effect | action of the stent placement apparatus of the 7th Embodiment of this invention. It is sectional drawing explaining the conventional stent placement apparatus. It is sectional drawing which shows the process of indwelling a stent in a body using the conventional stent indwelling apparatus. It is sectional drawing which shows the process of indwelling a stent in a body using the conventional stent indwelling apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer tube, 2 ... Inner tube (inner), 3 ... Stent, 5 ... Stopper, 6 ... Balloon, 7 ... Step part, 8 ... Reduced diameter part, 9 ... Reduced diameter mechanism, 11 ... Balloon, 21 ... Balloon, 32 ... cut, 33 ... pull wire, 41 ... tip, 51 ... tip, 61 ... tip, 62 ... balloon, S ... esophagus, Sa ... stenosis.

Claims (6)

A stent placement device for placing a tubular stent in the body,
An outer tube,
An inner to be inserted inside the outer tube,
A diameter-reducing mechanism disposed at the tip of the inner;
Have
The stent is interposed between the outer tube and the inner,
The diameter-reducing mechanism includes a large-diameter state that is larger than the outer diameter of the stent in a state where the entire stent is interposed between the outer tube and the inner, and from the outer tube to the body. And the outer diameter can be changed between a small diameter state that is smaller than the inner diameter of the stent in a state where the diameter is not expanded when the stent is exposed,
The diameter reducing mechanism in the large diameter state is locked to the tip opening by contacting the tip opening of the outer tube, and the outer surface of the outer tube is in contact with the tip opening and the diameter reducing mechanism. And the outer surface of the diameter-reducing mechanism are continuous, and have a shape that gradually becomes thinner from the locking portion with respect to the distal end opening toward the distal end .   The stent placement device according to claim 1, wherein the diameter-reducing mechanism is configured by a contractible balloon.   The stent placement device according to claim 2, wherein a step portion is formed at a portion of the outer periphery of the balloon that is engaged with the distal end opening of the outer tube.   The stent placement device according to claim 2 or 3, wherein the balloon is formed in a bowl shape.   The stent placement device according to claim 2 or 3, wherein the balloon is formed in a rhombus shape in a side view.   The stent placement device according to claim 2, wherein the balloon is disposed on a distal end side of the inner stent interposition position.

Images