JPH0510942B2 - - Google Patents

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a living body freezing probe for removing affected areas such as polyps and cancer cells generated on living tissues such as the throat, esophagus, and stomach. In particular, the present invention relates to an elongated tubular probe for freezing a living body that can be incorporated into an endoscope for observing inside a living body.

``Prior Art'' Conventionally, for example, as shown in FIG. A thin tubular probe 10 is formed to allow communication between the inner tube 2 and the middle tube 3 via the tip 1a, and the tip end side of the outer tube 4 located outside thereof is hermetically sealed with the tip plug 1, or an endoscope. After inserting the probe 10 or the endoscope into a living tissue such as the urethra or stomach, the probe 10 or the endoscope is inserted into a body tissue such as the urethra or stomach, and then the probe 10 or the endoscope is inserted through the inner tube 2 with the tip in contact with the affected area. A cryogenic fluid such as liquid nitrogen is poured into the tip plug 1 from the cavity 1a.
A freezing probe 10 is known, which removes heat from the affected area through the tip plug 1 by colliding with the inner surface of the affected area, and removes the diseased root portion of the affected area. Since the inner pipe 2 and the middle pipe 3 are communicated through the inner pipe 2 and the middle pipe 3, the vaporized fluid that has been heat removed by colliding with the tip plug 1 is exhausted through the middle pipe 3, and the amount of the vaporized fluid is exhausted together with the cryogenic fluid. By adjusting the temperature and amount introduced, the freezing depth and freezing range of the living tissue in contact with the tip plug 1 can be arbitrarily set, and the collision of the cryogenic fluid can be stopped and frozen based on judgment from external X-rays, etc. By thawing the affected area and repeating the above-mentioned freezing and thawing, it is possible to completely frostbite and kill only the diseased root part of the affected area, and as a result, the affected area can be removed and treated without performing surgical resection surgery. New treatments can be obtained.

Now, since the cryoprobe 10 is generally inserted into living tissue using the esophagus, etc.,
In the device, it is necessary to eliminate the possibility of erroneous freezing and melting when normal living tissue comes into contact with the outer periphery of the tip plug 1.
A vacuum is placed between the outer tube 4 and the outer tube 4 to maintain insulation.

"Problem to be Solved by the Invention" However, in order to maintain a reduced pressure (vacuum) state between the second conduit 3 and the outer tube 4, the outer tube 4 must have sufficient strength to withstand the pressure resistance. As a result, it was necessary to increase the wall thickness of the outer tube 4 or to form it from a rigid material, but this meant sacrificing flexibility, which significantly improved operability. This makes it difficult to bring the tip plug 1 into contact with a desired position within the living tissue.

Further, as shown in FIG. 2, the probe 10 is incorporated into an endoscope 20 together with a fiberscope, etc., and the affected part is extracted and removed while inspecting the position of the tip plug 1 using the fiberscope. If the wall thickness of the outer tube 4 is increased in order to maintain pressure resistance as described above, the outer diameter of the probe 10 will inevitably increase, making it difficult to incorporate it into the endoscope 20. becomes impossible.

Therefore, in such conventional technology, the disadvantages of the probe 10, namely, that it is extremely difficult to obtain flexibility and it is difficult to reduce the diameter to the extent that it can be incorporated into the endoscope 20, are problems that are extremely important in practice. Since the problem could not be solved, the biological freezing probe 10
Although it is clear that it is an extremely effective medical tool that can prolong life and provide prompt medical treatment by performing surgical operations without relying on open surgery, it has not yet been put into practical use. It was quite difficult to reach it.

In view of the drawbacks of the prior art, an object of the present invention is to provide a living body freezing probe that can achieve flexibility and diameter reduction even when the space between the inner tube and the outer tube is placed under vacuum. Accordingly, it is possible to provide an elongated tube-shaped living body freezing probe that can be incorporated into the endoscope 20 for inspecting inside the living body, or can be used without being attached to the endoscope.

"Means for Solving the Problems" The present invention provides a tip plug 1 that functions as an introduction hole or a discharge hole for a liquefied cooling fluid that freezes living tissue. The present invention relates to a living body freezing probe 10 in which a substantially ring-shaped space 5 formed between the outer tube 4 and a conduit located on the inner peripheral side thereof is placed under a vacuum to provide a heat insulation effect. .

The features of the present invention are as follows: (1) A metal tip member (tip plug) 1 having a concave cavity 1a on the back side, and an inner tube 2 held hollow with its tip opening facing the cavity 1a. A tip plug is arranged concentrically on the outside of the inner tube 2 via a first ring-shaped cavity 8, and its tip side is hermetically fixed to the rear end of the tip plug 1 located on the outer edge side of the cavity 1a. an outer tube 4 which is arranged concentrically on the outside of the inner tube 3 with a second ring-shaped cavity 5 interposed therebetween, and whose distal end is hermetically fixed to the outer circumferential side of the tip plug 1; and a laminate formed by alternately laminating metal foil 6a and resin mesh 6b interposed in the second ring-shaped space 5, the inner tube 2 being a small diameter flexible conduit. So, the middle tube 3
is formed of a thin-walled, non-corrosive metal capillary tube, and the outer tube 4 is formed of a thin-walled, non-corrosive metal capillary tube with a diameter of approximately 3 mm or less with high reflection efficiency, and the second ring-shaped space 5 is evacuated. On the other hand, without intervening a heating coil in the first ring-shaped space 8, the cooling liquid introduced from the inner tube 2 collides with the space 8, causing the tip plug to It is characterized in that it can be maintained under positive pressure by the vaporized fluid that absorbs heat from the living tissue through the vaporized fluid.

In this case, the inner tube 3 through which the vaporized cooling fluid passes after freezing the living tissue is preferably formed of a bellows-shaped metal flexible tube.

"Function" The elongated tubular living body freezing probe 10 that can be incorporated into the endoscope 20 for inspecting inside the living body as in the present invention.
In this case, it is necessary that the endoscope itself can be arbitrarily bent to follow the endoscope 2, and it is also necessary to achieve a reduction in diameter.

That is, in order to achieve diameter reduction, it is necessary to minimize the amount of intervening members (laminates) that prevent the tube from collapsing due to the curvature.

Therefore, in the present invention, pressure is maintained in the inner tube 2 located at the innermost position using a liquefied cooling fluid, and on the other hand, the first ring-shaped space 8 between the inner tube 2 and the middle tube 3 is
A positive pressure is maintained with the vaporized fluid after freezing the living body without intervening a heating coil, and the second ring-shaped space 5 on the inner circumferential side of the outer tube 4 is designed to eliminate the risk of freezing even normal living tissue. Since they are placed under a vacuum, they tend to collapse, but this is avoided by maintaining the spacing by a laminate 6 formed by alternately laminating metal foil and resin mesh.

In order to maintain bendability, the inner tube 2 is a flexible conduit with a small diameter, the middle tube 3 is a thin tube made of a thin non-corrosive metal, such as gold, and the outer tube 4 is a thin tube with a diameter of approximately It is preferable that each tube is formed of a thin-walled non-corrosive metallic thin tube of 3 mm or less, for example, made of gold.

In this case, since the middle tube 3 is formed as a non-corrosive metal thin tube, the curve is maintained even when the vaporized fluid passing through the middle tube 3 is exposed to extremely low temperatures.

It is also preferable that the inner tube 2 is formed of a non-corrosive metal thin tube, but since the cooling liquid before evaporation flows in the inner tube 2, the liquid can prevent exposure to extremely low temperatures. For this purpose, a small diameter flexible tube made of resin may be used.

Furthermore, although the outer tube 4 is not exposed to ultra-low temperatures, it is necessary to completely insulate it from normal living tissue, so it is made of a thin-walled, non-corrosive metal thin tube with high reflective efficiency. ing.

The inner tube 2 is held hollow with its tip opening facing the cavity, while the middle tube 3 has its tip airtightly fixed to the rear end of the tip plug located on the outer edge side of the rear cavity 1a, and is opened. Because of this, the cooling liquid introduced into the inner tube 2 can easily collide with the rear cavity, be vaporized, and be easily discharged through the first ring-shaped cavity 8. The first ring-shaped cavity 8 inside 3 is maintained under positive pressure by the vaporized fluid, while the second ring-shaped cavity 5 outside it is in a vacuum, so it bulges out relatively. A strong positive pressure is applied in the direction, so even if it is bent, it will not collapse.

Moreover, a second ring-shaped cavity 5 outside the middle tube 3
Since the inner tube 3 is held by the laminate 6, there is no possibility of bulging deformation even if the inner tube 3 is formed of a thin non-corrosive metal thin tube.

Also, the first ring-shaped cavity between the inner tube 2 and the middle tube 3
The fact that neither the heating coil nor the laminated body 6 is interposed in the heating coil 8 makes it possible to easily reduce the diameter between the two.
In particular, the outer tube 4 can be made to have a diameter of 3 mm or less, which not only ensures the above-mentioned curvature but also makes it possible for the first time to put into practical use a probe for freezing a living body that can be inserted into an endoscope.

Furthermore, since neither the heating coil nor the laminated body 6 is interposed in the first ring-shaped cavity 8, a discharge cavity for the vaporized fluid can be secured smoothly, and the cooling capacity of the chip plug is improved accordingly.

Furthermore, between the second ring-shaped space 5 located on the inner circumferential side of the outer tube 4, the pressure resistance for holding and placing it under vacuum is maintained in the ring-shaped space 5 without being maintained on the outer tube 4 side. Since the outer tube 4 is held by an interposed flexible laminate, the outer tube 4 can be made thinner regardless of the pressure resistance, in other words, the outer tube 4 can be easily made flexible and thinner. It can be achieved.

Therefore, according to the present invention, for the first time, it is possible to provide an elongated tube-shaped living body freezing probe 10 that can be incorporated into an endoscope 20 for inspecting inside a living body.
Such a configuration does not exist in any prior art.

Furthermore, since the laminate 6 is formed by laminating a resin mesh 6b and a metal foil 6a, the inner tube 2
It is also possible to effectively reflect the radiant cold heat from the inner tube 3, thereby making it possible to make the ring-shaped space 5 thinner and significantly improving the insulation efficiency. Further reduction in the diameter of the probe 10 can be achieved.

Furthermore, the fact that the outer tube 4 is formed of a thin body made of non-corrosive metal provides corrosion resistance and prevents the surface of the probe 10 from being eroded by stomach acid, etc., and also prevents harmful metals from leaching into the body. preferred.

Also, between the outer tube 4 and the inner tube 3 located on the inner circumferential side,
Since a non-contact state is always maintained by the laminated body 6 in which the resin mesh 6b and the metal foil 6a are laminated, the two tubes 3 and 4 will come into contact no matter how the probe is bent. This is preferable in terms of maintaining the heat insulation effect.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this example are as follows, unless otherwise specified.
This is not intended to limit the scope of the invention, but is merely an illustrative example.

FIG. 1 is a front sectional view showing the internal structure of a living body freezing probe 10 according to an embodiment of the present invention.

The probe 10 has a first
A flexible concentric triple tube consisting of a conduit 2, a second conduit 3, and an outer tube 4 is formed by sealing the distal end side with a metal tip plug 1, and the outer tube 4 and the second conduit 3 are
A laminate 6 made of a nylon resin material is spirally wound between the two. These members will be explained in detail below.

The tip plug 1 has a cylindrical plug shape with a diameter slightly smaller than that of the outer tube 4, and has an arc-shaped space 1a on the rear end side, and has an R-shaped front end side 1b that contacts living tissue. , probe 10
To be formed so that it can be easily inserted without damaging body tissues during insertion.

The plug 1 has a tapered rear end outer circumferential surface 1c so as to be able to come into contact with the enlarged diameter surface of a second conduit 3, which will be described later.
After fitting it into the outer tube 4 until it comes into contact with the expanded diameter surface,
A ring-shaped space formed between the outer tube 4 and the second conduit 3 is welded to form an airtight seal in the ring-shaped space 5 formed between the outer tube 4 and the second conduit 3.

Next, each tube forming the concentric triple tube will be explained in order. The first conduit 2 has a diameter of about 0.5 m/
mφ, thin diameter gold with a wall thickness of about 0.1mm
It is formed of a thin tube or a nylon resin pipe, and its tip extends into the arcuate space 1a of the tip plug 1, and the vaporized liquid nitrogen inserted into the first conduit 2 is a jet gas-like fluid. The structure is such that it collides with the inner wall surface of the tip plug 1.

The second conduit 3 is formed of a thin metal tube with a diameter of about 1.7 m/mφ and a wall thickness of 0.1 to 0.2 mm.The tip of the second conduit 3 is enlarged to have a figure-eight cross section, and a tip plug is attached to the enlarged diameter surface 3a. The rear end surface 1c is formed so as to be able to come into contact with it.

As will be described later, a so-called positive pressure state is maintained in the ring-shaped space 8 formed between the second conduit 3 and the first conduit 2 through which the vaporized nitrogen gas after colliding with the tip plug 1 passes. Therefore, the laminated body 6 as described later is not particularly required, and on the contrary, if the laminated body 6 is inserted, the area through which the vaporized nitrogen gas passes becomes smaller and the passage resistance increases, which is not preferable. However, if the degree of bending of the probe 10 is increased, the second conduit 3 without the laminate 6 interposed therein may be crushed. It may be formed to improve flexibility.

The outer tube 4 is a pipe made of gold in order to maintain flexibility, corrosion resistance, and a predetermined reflection effect on the inner wall side, and its outer diameter is 2.6 m/mφ or less, specifically 2.4 to 2.6 m/mφ and the wall thickness is set to about 0.1 to 0.2 mm. As a result, the outer diameter of the cryoprobe 10 of this embodiment can be suppressed to 2.6 m/mφ or less, so that it can be inserted into the hole diameter portion 21 of the existing endoscope 20.

Inside the ring-shaped space 5 of the outer tube 4 and the second conduit 3, there is a thin layered laminate 6 formed by wrapping aluminum foil 6a and nylon mesh 6b in multiple layers.
is interposed therebetween, so that when the inside of the ring-shaped space 5 is placed under vacuum, the outer tube 4 is not pinched to the second conduit 3 side, and the distance is maintained by the thickness of the laminate 6. Due to the presence of the nylon mesh 6b, the ring-shaped space 5 of the laminate 6 is naturally ventilated up to the tip, and can be easily evacuated.

Therefore, the inside of the ring-shaped space 5 is maintained in a vacuum state by being evacuated in advance and then sealed.

Next, the operation of this embodiment will be explained based on FIG. 2.

The cryoprobe 10 configured as described above is inserted into the protruding diameter portion 21 of the existing endoscope 20, and the endoscope 20 is inserted into the stomach wall 30 with its distal end protruding. Then, using an observation window provided at the tip of the endoscope 20, a fiberscope (none of which are shown), etc., the tip of the cryoprobe 10 is inserted into the affected area.
1, the ring-shaped space 5 between the outer tube 4 and the second conduit 3 is kept in a vacuum state by the pump and sealed, and the pressure inside the first conduit 2 is higher than normal pressure. The liquid nitrogen 32 is introduced by introducing liquid nitrogen 32, or by evacuating a ring-shaped space 8 (described later) using a pump.
2 is ejected from the tip of the first conduit 2 toward the concave space 1a of the tip plug 1 in the form of a jet stream.

As a result, the affected area 3 is inserted through the tip plug 1.
1 is frozen, and the liquid nitrogen 32, which is in a state where it is easy to become a jet injection gas, evaporates due to its heat absorption (heat removal), and the vaporized nitrogen gas 33 flows between the second conduit 3 and the first conduit 2. While passing through the ring-shaped cavity 8, the liquid is evacuated or discharged to the atmosphere from the outlet end of the second conduit 3.

At this time, since the vaporized nitrogen gas 33 flowing inside the second conduit 3 is a gas, it serves as a heat shield, and there is no contact between the second conduit 3 and the outer tube 4 due to the laminate 6. While maintaining the state of
Moreover, since the vacuum state is maintained, the cold heat of the liquid nitrogen 32 transferred to the second conduit 3 side can be completely blocked, and the effects of the present invention can be smoothly achieved.

Returning to the original state, the amount of vaporized nitrogen gas discharged from the second conduit 3 and the amount and temperature of the liquid nitrogen 32 introduced into the first conduit 2 are adjusted by a computer based on a predetermined algorithm. By doing this, the freezing depth and freezing range of the living tissue in contact with the tip plug 1 can be arbitrarily set, and the introduction of liquid nitrogen 32 is stopped based on judgment from external X-rays, etc., and the frozen affected area is thawed. By repeating freezing and thawing, it is possible to completely frostbite only the diseased root part of the affected area, killing it and removing it, and the destroyed cells in the affected area are then decomposed by the body's self-cleaning action and expelled from the body. The prescribed surgery to remove the affected area is completed.

"Effects of the Invention" Therefore, according to the invention, since the inner peripheral side of the outer tube is made of a laminate having a pressure-resistant effect for placing under vacuum, the outer tube can be made thinner and have a smaller diameter regardless of the pressure-resistant strength. This makes it possible for the first time to provide an elongated tubular probe for freezing a living body that can be incorporated into an endoscope for observing inside a living body, and its practical value is extremely large.

[Brief explanation of drawings]

1 to 3 show a cryogenic probe according to an embodiment of the present invention, FIG. 1 is a front sectional view, FIG. 2 is a schematic diagram showing the state of use, and FIG. 3 is a modification of the probe. FIG. FIG. 4 shows a cryoprobe according to the prior art.

Claims (1)

[Scope of Claims] 1. A metal tip member having a concave cavity on the back side, an inner tube held hollow with the tip opening facing the cavity, and a first ring-shaped member on the outside of the inner tube. a middle tube arranged concentrically with a cavity in between, the distal end of which is airtightly fixed to the rear end of a metal tip member located on the outer edge side of the cavity; and a second ring outside of the middle tube. an outer tube that is arranged concentrically with a ring-shaped space in between and whose distal end is hermetically fixed to the outer circumferential side of the metal tip member; and a metal foil that is interposed in the second ring-shaped space. and a laminate formed by alternately laminating resin meshes, the inner tube being a small diameter flexible conduit, the middle tube being a thin non-corrosive metal capillary tube, and the outer tube being a thin-walled non-corrosive metal capillary tube. About 3
The second ring-shaped space is maintained under vacuum, while a heating coil is interposed in the first ring-shaped space. The cooling liquid introduced from the inner tube collides with the space, and the space is maintained under positive pressure by the vaporized fluid that absorbs heat from the living tissue through the metal tip member without causing any damage. A probe for living body freezing. 2. The living body freezing probe according to claim 1, wherein the probe is inserted into an endoscope.