JPS6243693B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a high-frequency ablation device that can be introduced into a body cavity and bloodlessly remove tissue such as a polyp using high-frequency current.

Generally, this type of high-frequency ablation device has a snare wire that forms a loop at the tip of a tube that can be protruded and retracted, and the snare wire can be protruded and retracted from the proximal side via an operating cable inserted into the tube. It was designed as
(see publication). When using this, proceed as follows. In other words, for example, after the polyp is introduced endoscopically into a body cavity, a snare wire is protruded and hooked onto the polyp, the snare wire is pulled inside the tube to bind the stem of the polyp, and then a high-frequency current is applied and the polyp is cut by cauterization. It is something to do. Therefore, according to this cutting means, since the cutting is performed by cauterizing with high frequency current,
Blood vessels in the stem of a polyp have the advantage of being able to be removed bloodlessly by being compressed by protein coagulation and edema.

However, in actual use, there were the following drawbacks.

Depending on the size and nature of the polyp, when hooking a loop of snare wire around the polyp to bind it, if you do not pull the snare wire into the tube the right amount, it may mechanically break before the high-frequency current is applied.
In some cases, there was a risk of major bleeding.

It requires skill to actually adjust the amount of binding by the snare wire.

After applying a high-frequency current, the snare wire is further pulled into the tube to cut it. However, if the drawing speed is too slow, the surrounding tissue may be overcooked and perforation may occur in the same area after the incision. . Moreover, if it is applied too early, there is a problem that the hemostasis effect on blood vessels is weak and bleeding may occur. In other words, it was difficult to reliably perform the treatment at an appropriate retraction speed, making it impossible to perform the treatment safely.

The present invention has been made focusing on the above circumstances,
The purpose is to provide a high-frequency ablation device that can safely and easily ablate tissue.

Hereinafter, each embodiment of the present invention will be described based on the drawings.

1 to 3 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a flexible tube made of, for example, a synthetic resin material, and the tube 1 is configured to be inserted into a treatment instrument insertion channel of an endoscope (not shown). A disk-shaped slider 2 is inserted into the distal end portion 1a of the tube 1 so as to be movable forward and backward, and one end of a snare wire 3, which will be described later, is attached to the slider 2. The slider 2 is formed with a through hole 4 through which the other end of the snare wire 3 is inserted. Also,
A stopper 5, which comes into contact with the slider 2 when the snare wire 3 is pulled into the tube 1, is fixedly attached to the middle of the other end of the snare wire 3. In addition, a slider 2 is installed at the tip of the tube 1.
A locking pipe 6 is fitted and fixed to restrict the final forward position of the shaft.

The snare wire 3 is made by twisting thin wires of a shape memory alloy, such as a Cu-Zn-Al alloy or a Ti-Ni alloy, which undergoes reverse transformation from the martensitic phase back to the matrix phase. The ending temperature Af is above body temperature, for example 50
℃ is used. The shape at high temperature (crystal structure is the matrix) (initial processing state) is the first.
The state shown by the two-dot chain line, which is shorter than the solid line in the figure, is set. In other words, it contracts into a hairpin shape and is drawn into the tube 1. Further, the snare wire 3 is plastically deformed and stretched at the body cavity temperature (before and after 37° C.) with the bent tip portion 7 remaining as shown by the dotted line in FIG. Therefore, at this time, the shape memory alloy undergoes martensitic transformation to generate a martensitic phase. Also, this stretched snare wire 3
is pulled into the tube 1, and at the final position where it cannot be pulled in any further, the vicinity of its bent tip 7 slightly protrudes from the tip of the tube 1.
It is regulated as shown by the solid line in the figure.

On the other hand, a hollow pipe-shaped operating section main body 8 is connected to the base end of the tube 1. An operating slider 9 is slidably fitted into the operating section main body 8, which allows the snare wire 3 to be advanced through a metal operating cable 10 inserted into the tube 1. It is designed to be manipulated. That is, the other end of the snare wire 3 is connected to the tip of the operating cable 10 via the connecting member 11, and the connecting base 12 is connected to the base end of the operating cable 10.
is attached. A contact pin 13 provided on the operation slider 9 is connected to this connection base 12. This contact pin 13 penetrates through a long hole 14 formed in the side wall of the operating section main body 8.
It is designed to be able to slide forward and backward along the Further, on the peripheral surface of the proximal end of the operation section main body 8, a contact section 15 consisting of a stepped portion is formed to which the operation slider 9 is applied and prevents the operation slider 9 from retreating further. It is now set. Note that a finger ring 16 is provided at the base end of the operating section main body 8.

Next, a method of using the high frequency ablation device in the above embodiment and its function will be explained. First, in preparation for introduction into the body cavity, the operation slider 9 is retreated to the end that contacts the abutting portion 15, as shown in FIG. The operating cable 10 is then pulled, and the snare wire 3 is thereby drawn into the tip of the tube 1, as shown by the solid line in FIG. However, the bent tip 7 of the snare wire 3 remains slightly protruding from the tip of the tube 1.

Therefore, the endoscope is introduced into the body cavity through the insertion channel, and the tip of the tube 1 is directed toward the polyp 17. Next, by advancing the operating slider 9, the snare wire 3 is pushed out via the operating cable 10, and the slider 2
When the snare wire 3 is moved toward the tip side until it hits the snare wire 3, the snare wire 3 protrudes from the tip of the tube 1 and forms a loop, as shown by the dotted line in FIG. After this,
As shown in FIG. 3A, the loop portion of the snare wire 3 is hooked onto the polyp 17. This time, conversely, by retracting the operating slider 9 to the end that touches the abutting portion 15, the snare wire 3 is pulled in through the operating cable 10, and the stem of the polyp 17 is tied up as shown in FIG. 3B. . At this time, since the bent tip 7 of the snare wire 3 slightly protrudes from the tip of the tube 1, the polyp 17 is not mechanically cut. After this, contact pin 1
When a high frequency generator is connected to the snare wire 3 and a high frequency current is applied, the stem of the polyp 17 bound to the snare wire 3 is cauterized. Further, since the portion of the snare wire 3 that directly contacts the polyp 17 is simultaneously heated to a high temperature higher than body temperature, the shape memory alloy forming it returns from the martensitic phase to the parent phase.
Therefore, the snare wire 3 is contracted and completely drawn into the tube 1. Then, due to this movement, the cauterized area progresses further into amputation, and the third
It will be completely cut as shown in Figure C.

In addition, the polyp 17 is removed by the snare wire 3.
However, even if the stem is extremely large, the length of the portion of the snare wire 3 surrounding the stem increases accordingly, increasing the portion heated by the high-frequency current. Therefore,
Since the amount of contraction of the snare wire 3 increases accordingly, the snare wire 3 is completely drawn into the tube 1 in any case. Therefore, regardless of the size of the polyp 17, it can be reliably cut.

Furthermore, as the shape memory alloy is heated, the speed at which it returns from the martensitic phase to the matrix phase becomes optimal depending on the heating and cauterization conditions, so that neither excessive cauterization nor undercauterization occurs.

Note that when the snare wire 3 cools down by being left alone, it returns to its original state and can be used again.

FIG. 4 shows a second embodiment of the invention. In this embodiment, the shape of the snare wire 3 is formed into a hexagonal loop shape as shown by the solid line, and further,
When the snare wire 3 is pulled into the tube 1, a restriction pipe 18 is installed in the tip of the tube 1 to prevent the snare wire 3 from being pulled in any further by hitting the slider 2. Incidentally, the dotted line indicates the snare wire 3 in the stretched state and in the retracted state, and at this time, the bent tip portion 7 slightly protrudes from the tip of the tube 1. Also,
The two-dot chain line indicates the state after cauterization and heating.

FIG. 5 shows a third embodiment of the invention. In this embodiment, the snare wire 3 is formed into a coil shape. By forming the snare wire 3 into a coil shape in this manner, the actual length of the snare wire 3 can be increased many times, and the amount of contraction can be increased accordingly.
In other words, the cutting force can be increased compared to those of the first and second embodiments. Note that the dotted line indicates the most retracted state in the normal extended state, and the two-dot chain line indicates the state after cauterization and heating.

FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, the snare wire 3 is formed into a hook shape instead of a loop shape, and the portion inside the tube 1 is bent into a coil shape. Also,
This snare wire 3 is formed of a single wire over its entire length. In addition, the dotted line shows the state when it is pulled in the most in the normal stretched state, and the two-dot chain line shows the state after cauterization and heating.

As explained above, in the high-frequency ablation device of the present invention, the snare wire is formed of a shape memory alloy, and in the normal retracted position where it is stretched, it remains without being completely retracted from the tip of the tube, and is heated by the high-frequency current. This allows the tube to contract and be drawn into the tube. Therefore, at the stage of binding tissues in the body cavity, such as polyps, with the snare wire, the vicinity of the tip of the snare wire remains without being drawn into the tube, so there is no need to mechanically cut the polyp. There is no risk of major bleeding. In other words, there is no need for sophisticated operations to finely adjust the amount by which the snare wire is pulled in and to set the amount of binding, and the device can be operated with confidence, and does not require any particular skill. Furthermore, after binding the tissue,
When a high-frequency current is supplied, it contracts depending on the heating and cauterization conditions. In other words, since the cutting is performed while tracking at an optimal speed, there is no possibility of perforation due to excessive cauterization or bleeding due to undercauterization. In addition, there is no particular need to adjust the amount of tightening depending on the size of the tissue to be excised, and it can be easily used without requiring any skill.

[Brief explanation of the drawing]

Fig. 1 is a sectional side view of the tip of the first embodiment of the present invention, Fig. 2 is a sectional side view of the operating portion thereof, and Fig. 3 is a sectional view of the operating portion thereof, showing the first embodiment of the present invention. Similarly, FIG. 4 is a side sectional view of the distal end showing the second embodiment of the present invention, and FIG. 5 is a diagram showing the distal end of the third embodiment of the present invention. FIG. 6 is a side sectional view of the distal end of the fourth embodiment of the present invention. 1...tube, 2...slider, 3...snare wire, 5...stopper, 6...locking pipe,
7... Bent tip, 8... Operating unit main body, 10...
Operation rope, 15...Abutment part, 17...Polyp,
18...Restricted pipe.

Claims (1)

[Claims] 1. A high-frequency ablation device in which a snare wire that protrudes and retracts when operated from the proximal side is inserted into the distal end of the tube, and the snare wire cauterizes and cuts the tissue while tightening it, and the snare wire is made of a shape memory alloy. 1. A high-frequency ablation device characterized in that the tube remains in the normal retracted position without being completely retracted from the tip of the tube, and is set to be drawn into the tube when heated by a high-frequency current.