JPH0252672A - Mechanochemical catheter - Google Patents

Abstract

PURPOSE:To control a swelling speed and swelling quantity from the outside so as to decrease the pain to be given to a patient by packing a water absorptive high-polymer gel into a flexible container and providing a liquid injecting tube and liquid discharging tube. CONSTITUTION:The water absorptive high-polymer gel 1 consisting of an ion exchange resin is packed into the container 2 of a tube, balloon, etc., made of a rubber bag or high-polymer film. This device is inserted into the tube or canal duct in the body and is so pushed therein that the narrow part is positioned in the central part of the part packed with the ion exchange resin. Water flows out of the liquid discharge tube 6 by injecting the water into the liquid injecting tube 5 from the outside of the body, but the water swells the water absorptive high-polymer gel 1 at this time, then the container 2 swells and expands the narrow part while exerting pressure thereto. The time to attain the swelling equil. is short and the control of the swelling speed and swelling quantity from the outside is possible. The large swelling pressure is locally generated and since the swelling is not high, less pains are given to the patient.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mechanochemical catheter used to widen a pathological stenosis in a portion of a duct within the body.

[Problems to be solved by conventional technology/inventions] Many water-absorbing polymer gels (polymer electrolyte gels, ion exchange resins,
collagen, water-absorbing hydrogel, water-absorbing rubber, etc.)
The gel itself can expand its volume by absorbing water from a dry state, that is, it can swell. If the swelling is mechanically restrained, swelling pressure is generated. ° Most of these gels can also absorb and shrink low concentration salt solutions such as saline. There are also gels that contract with acid and swell with alkali, and others that contract with acid or alkali and swell with water. In this way, the solution is selectively absorbed and
Polymers whose gel volume swells and contracts as a result of this, and which directly perform mechanical work against external force (load) or pressure, are called mechanochemical systems. Recently, several materials have been synthesized and commercially available as water-absorbing polymers (
Aquakel (Tamago Rubber Chemicals ■), Sumikagel (Sumitomo Chemical Oki), Prauetsu (Mitsubishi Yuka ■), etc.). For example, Sumikagel has a small swelling effect, but it has a significant water-absorbing effect, and some products include it in diapers.

There is also an electrolyte gel that is made of a copolymer having acrylamide as its main chain and is swollen with water in a mixed solvent of an organic solvent and water. However, since the 1950s, typical water-absorbing polymers have been polyelectrolyte gels made by crosslinking polyacrylic acid or polymethacrylic acid with polyvinyl alcohol, and ion exchange resins of the styrene/divinylbenzene/sulfonic acid type with a low degree of crosslinking. The styrene pot would be a divinylbenzene copolymer ion exchange resin. Depending on the degree of crosslinking, these can be 1.5 to 3 times the length (volume 3
It swells to about 30 times to 30 times) and shrinks to a degree close to a dry state by 3IloR/I saline solution. The swelling pressure generated during swelling is theoretically at its maximum value of 100 atmospheres or more. In addition, polyacrylic acid and polyvinyl alcohol are used as food additives, and the above-mentioned ion exchange resins (for example, DOWEX) are used as raw materials for drugs.They have low toxicity to living organisms, and water and low-concentration saline solutions are also used in humans. is harmless.

On the other hand, one of the surgical treatment techniques is to use air balloons to remove pathological strictures in parts of various tubes and canals in the human body, such as the esophagus, large intestine, anus, urethra, and birth canal. Catheters may be used to enlarge the Air is injected into the latex hollow tube or bag from the outside to inflate the tube or bag, but there is a risk of patient pain and bag rupture due to rapid expansion. Further, similar problems may occur with hydraulically driven balloon catheters. In addition, in the case of a pneumatic type, only a gauge pressure of 5 atmospheres can be applied at most, but if the stenosis is hard and the confining pressure is large, the air balloon will take on a gourd shape, unnecessarily compressing and expanding nearby normal areas. However, the stenotic area hardly expands, and no therapeutic effect can be expected. Furthermore, metal bougie catheters of various diameters are used to expand the urethra, but these catheters also cause great pain to the patient and pose a risk of damaging the inner wall of the urethra.

Based on these technologies, a device for enlarging the cervix using water-absorbing hydrogel was published in Japanese Patent Publication No. 59-50134.
It is described in Publication No. 5. However, after such a device is inserted into the body, it swells by absorbing body secretions from the outer surface of the cylindrical gel at the inserted site, and the diffusion rate of the liquid in the homogeneous polymer gel is low. The drawback is that the swelling rate is extremely slow.

Another drawback is that the swelling rate and amount of swelling cannot be controlled externally.

The present invention enables the injection of liquid such as water from the outside.
Swelling speed and amount can be controlled externally, generating greater swelling pressure than conventional air balloon catheters, causing less pain to the patient, and for enlarging pinched areas without damaging the application site. The purpose of the present invention is to provide a mechanochemical catheter.

[Means to solve the problem]

The present invention is a cylindrical or spindle-shaped catheter in which a water-absorbing polymer gel is filled in a stretchable flexible container, and the catheter is used for injecting a liquid from the outside to swell the water-absorbing polymer gel. A tube and a liquid discharge tube are provided to discharge the injected liquid.A liquid such as water is injected from outside the body, and at the same time, the liquid discharge tube is depressurized with air using an aspirator, etc. This invention relates to a mechanochemical catheter that is used to promote the flow and diffusion of liquids such as water in the body, and to expand the pathologically constricted parts of internal canals and tracts by swelling a polymer gel.

The present invention relates to a flexible tube or bag filled with water-absorbing polymer gel and provided with a liquid injection tube and a liquid discharge tube, and this is called a mechanochemical catheter.

In other words, when water is injected into a water-absorbing polymer that is dry or contracted due to salt, it swells in volume and generates swelling pressure, which can be used to expand and maintain narrowed areas in the human body's canals and canals. This surgical treatment is intended.

A dry or deflated catheter filled with water-absorbing polymer gel is inserted into a narrowed part of a canal or duct in the human body.
By injecting water or other liquid from outside the body through the liquid injection tube with a syringe, or by reducing the pressure of the air in the liquid discharge tube using an asviter, etc., the flow and diffusion of the liquid inside the catheter is promoted and controlled, and the gel inside is reduced. It swells itself and gradually enlarges the narrowed area, and after maintaining the enlarged state for a certain period of time,
The intention is to either remove the catheter as is, or to shrink the gel by injecting a salt solution or the like from outside the body, and then remove the catheter.

〔Example〕

The form of water-absorbing polymer gel is often in the form of granules like ion exchange resins, but there are also cases in which two types of granules are mixed, granules and homogeneous polymers are mixed, and granules are used. There are various forms, such as those consisting of a body layer and a gel layer, and those consisting only of a homogeneous gel.

There are no particular limitations on the material for the water-absorbing polymer gel.
Specific examples include, as mentioned above, polymer electrolyte gels (ion exchange resins, polyacrylic acid or polymethacrylic acid cross-linked with polyvinyl alcohol, etc.), water-absorbing polymers recently synthesized in Japan (Aquaker ,
Examples include Sumikagel, Prawet, acrylamide copolymers, etc.).

Among these, ion exchange resins with high swelling degree, especially styrene/divinylbenzene/sulfonic acid type 17) H
Type DOWEX 50V (XI, X2, X4) and styrene/divinylbenzene copolymer type CI type DOW
EX 1 (Xi, 'X2, x3, x4) (manufactured by Dow Chemical Company, USA) is the most effective. This also applies to powders of polyacrylic acid or polymethacrylic acid gels.

If the above-mentioned water-absorbing polymer is also used in the form of granules or powder, it will have the same effect as polyacrylic acid gel powder. In any case, the swelling speed of a homogeneous gel is very slow, and if it is made into granules, the liquid passes through the voids in the granules, so if an aspirator is used, the liquid can flow quickly due to its depressurizing effect. Become. When the radius of the grain is small, the swelling speed of each part is fast, and the swelling speed of the grain is
This is much faster than using gel alone.

In addition, there are no particular limitations on the material for flexible containers such as tubes or bags that contain water-absorbing polymers, but latex (natural rubber), silicone rubber, polyurethane, etc. are suitable, and polymer membranes that are flexible, thin, and hard to break are suitable. A tubular or bag-shaped one is preferable. Further, it is preferable to make the tip round or tapered because it facilitates insertion into a tube. Furthermore, the degree of swelling in the radial direction can be improved by tapering the tip of the tube as shown in FIG.

In order to prevent injection liquid (water, salt solution, etc.) from outside the body from leaking into the body, it is preferable that the material of the flexible container does not allow such injection liquid to pass through.

In addition, when the gel inside the container swells, in order to improve the efficiency of swelling in the radial direction of the flexible container (direction perpendicular to the long axis of the container), a restraining member such as a thread is placed along the long axis of the container. It is also effective to embed the container into a container and then wrap the container around the outer surface of the container in the longitudinal direction. Threads include cotton thread for implantation, hanging thread for wrapping, and surgical suture thread (
Silk braid, nylon braid, polyester braid) are effective. In any case, it is best to use a material that has high breaking strength, is difficult to stretch, and has a high outsideness compared to the container material, such as latex.

Furthermore, the mechanochemical catheter of the present invention is provided with a liquid injection tube for externally injecting a liquid that swells the water-absorbing polymer gel, and a liquid discharge tube for discharging the liquid to the outside.

There are no particular limitations on the material for the liquid injection tube and liquid discharge tube, but in order to insert a mechanochemical catheter into a tube or canal inside the body from outside the body using a liquid injection tube or the like as a support shaft,
The liquid injection/discharge pipe must have appropriate rigidity and bending resistance, and may be made of materials such as Teflon, silicone, vinyl chloride, metal, or a composite material of plastic and wire.

The liquid injection/discharge pipe can be inserted into the container via a fastening stopper, as shown in FIG. When a flexible container is provided with plugs at its upper and lower ends and a thread is wound around the surface of the container along its long axis, it is convenient to wind the thread around the plugs at the upper and lower ends. High breaking strength (2-3 kg or more)
Wrap the thread around 4 to 24 times at equal angles. The material for the fastening stopper may be rubber, but a harder plastic stopper (such as Teflon) is preferable because the thread will not get stuck in the stopper. Flexible containers can also be made by wrapping polymer membranes such as latex around these stoppers and tying them tightly with thread.

In addition, the liquids injected from the outside are drinking water and salt solutions such as Na (J), which are harmless to the human body (acid, alkali, and organic solvents are not included in the liquid used), and these enter the body after the gel swells or contracts. Although some amount of the drug may be released, it is safer to circulate it within the catheter and release it outside the body instead of releasing it into the body.

Next, embodiments of the mechanochemical catheter of the present invention will be described based on the drawings.

Figure 1 shows the configuration of a liquid-releasing mechanochemical catheter filled with ion exchange resin, and Figure 2 shows the configuration of a liquid circulation type mechanochemical catheter filled with powder (pieces) of ion exchange resin or polymer electrolyte gel. Figure, 3A-3
Figure B is a cross-sectional view of the liquid injection tube that also serves as the liquid discharge tube in Figure 2, Figure 4 is a configuration diagram of a liquid circulation double-tube mechanochemical catheter filled with ion exchange resin, and Figure 5 is a cross-sectional view of the liquid injection tube that also serves as the liquid discharge tube in Figure 2. A configuration diagram of a liquid circulation type two-tube mechanochemical catheter filled with ion-exchange resin. Figure 6 shows a discharge tube inserted into a glass filter installed at the bottom end of a container filled with ion-exchange resin; Figure 7 is a configuration diagram of a mechanochemical catheter with tapered portions and a liquid circulation type two-tube type mechanochemical catheter. Figure 8 shows a liquid circulation type mechanochemical catheter made solely of a cylindrical homogeneous water-absorbing polymer.

In the figure, (1) is a water-absorbing polymer gel such as an ion exchange resin, a polymer electrolyte gel, or a water-absorbing polymer; (2)
(3) is a container such as a rubber bag or a tube or balloon made of a polymer membrane, (3) is a restraining member such as a thread that is inserted into the container to give directionality when the water-absorbing polymer gel swells, (4) )
is a glass filter; (5) is a liquid injection tube; a rigid hollow tube embedded in a water-absorbing polymer gel; (5a) is a liquid injection tube connected to the mechanochemical catheter body;
(6) is a liquid discharge tube, which is a hollow tube embedded in water-absorbing polymer gel, (6a) is a liquid discharge tube connected to the mechanochemical catheter body, and (7) is a liquid injection tube or liquid discharge tube. (8) is a water-absorbing polymer gel layer that has the effect of fixing a layer of water-absorbing polymer gel made of an ion exchange resin layer, etc., and (9) distinguishes between liquid injection and discharge. Shows the diaphragm inside the circular pipe.

Figure 1 shows a container (2J) consisting of a rubber bag in which a restraining member (3) such as a thread is embedded, and a water-absorbing polymer gel (1) made of an ion exchange resin is filled in the container (2). The upper and lower ends are cylindrical glass filters (4) that close the container (2) to prevent the ion exchange resin from flowing out.

The ion exchange resin is kept in a dry state or in a contracted state with a several standard solution of sodium chloride.

The hollow liquid injection tube (5) is an extension of the container (2) or the container (
'2J is the inlet tube for the solution that is firmly connected to the pipe. Insert this device into a canal or canal in the body 7, and insert the liquid injection tube (5) so that the narrowed part is located in the center of the part where the ion exchange resin is clogged.
Push through. By injecting water into the liquid injection tube (5) from outside the body, water flows out from the liquid discharge tube (6), but the water-absorbing polymer gel (1) made of ion exchange resin
The rubber bag container (2) swells as shown by the two-dot chain line in FIG. 1, and expands while applying pressure to the narrowed area. Swelling can be controlled and maintained by adjusting the volume and time of injected water, like an intravenous drip. Once the enlarging work is completed, the device may be removed as is, but after injecting a salt solution through the liquid injection tube (5) to shrink it slightly so that there is no friction between the constriction and the container (2), remove the tube.・You can pull it out from the road.

According to a prototype experiment, a container (2) made of a rubber bag with an outer diameter of 25III11 and a dried ion exchange resin (DOWEX 1,
When I packed 30g of XL, 50-100aesh) and poured water as needed, the outer diameter of the center of the rubber bag container (2) changed from 2611III to 48mm after 4 minutes, 50mm after 10 minutes, and 57mm after 25 minutes. It swelled to a diameter of 42 am s 1 after 2 minutes by injection of 0.5N sodium chloride solution.
It contracted to 40 am after 0 minutes.

Figure 2 shows that a water-absorbing polymer gel (1) made of ion exchange resin or polymer electrolyte gel powder is filled into a container ('2J) made of a flexible bag, and the lower end is closed inside the granular packing. The liquid injection tube (5) is embedded.The container (2) and the liquid injection tube (5) are tied together at the upper and lower ends with strings (101) to prevent particles from flowing out.The liquid injection tube (5) is It is an empty tube with a small hole (cut by a sword).

The small holes (7) can be made smaller in diameter than the dry grains using a laser processing machine, etc. If the holes are larger than the dry grains, cover the surfaces of the tubes (5) and (6) with filter paper or cloth. You can also do that. By injecting water from the top, water is released from the small pores into the dry granules, forming a water-absorbing polymer gel (1).
The granules swell in the radial direction of a container (2) consisting of a bag or tube, thereby enlarging the narrowed area. Liquid injection tube (5)
Due to its rigidity, the particles cannot swell inward. An outlet for the air in the liquid injection pipe (5) is required, and in order to create a liquid circulation system, the liquid injection pipe (5) should be a double pipe with a partition plate as shown in Figure 3A. If both pipes are provided with small holes (7) and one is used as an injection pipe and the other as a discharge pipe, a liquid circulation system will be created through the granules. In addition, in the case of a double pipe as shown in Fig. 3B, small holes (7) are attached to both the inner and outer pipes, but the outer v,! It is effective to fill the tube halfway up the inner tube, and inject from the inner tube (7) and discharge from the outer tube.A syringe may be used to drain the liquid, but if you connect an aspirator and reduce the pressure, the liquid circulation speed will be reduced. is significantly improved.

The same applies to other figures.

Figure 4 shows a rubber bag container (2) containing a glass filter (4) at the top of the opening and a restraining member (3) such as a string, filled with a water-absorbing polymer gel (1) made of ion exchange resin. In this structure, water is injected through the central liquid injection tubes (5) and (5a), and water is released from the small hole (7) of the liquid injection tube (5) in the resin filled bed. It soaks into the resin layer and causes the resin to swell. This is a liquid circulation system in which water is discharged from a liquid discharge pipe (6), which is a double-walled outer peripheral pipe, through a glass filter (4). The liquid injection pipe (5a) may be made of the same material and dimensions as the liquid injection pipe (5), but may also be made of the same material and dimensions as the liquid injection pipe (5).
The more flexible the better. It is also effective to replace the inlet pipe and the outlet pipe and use the pipe (5) having the small hole (7) in the center as the outlet pipe.

According to the prototype experiment, the length of the container (2) made of a hollow tube is 6.
0ml5 outer diameter 4a+m (made of latex, dipping molding), outer diameter of liquid injection tube (5) 1■
(Teflon tube), liquid injection pipe (5a) and liquid discharge pipe (
6) is made of silicone tube and contains water-absorbing polymer gel (1)
Toshition exchange resin (DOWEX 1, Xi, 50
A container consisting of a tube with an outer diameter of 4II11 (2 ) 4 minutes after 71.6 minutes after 7.
5111 and injected with 1N sodium chloride solution (
7.5 ni after 3 minutes by 1 cc every minute)
It contracted to 5.5 aua after 6m11,7 minutes.

FIG. 5 shows a liquid circulation system in which liquid injection pipes (5) and (5a), which are inlet pipes, and liquid discharge pipes (6), (6a), which are outlet pipes, are arranged in parallel. The tips of both tubes (5) and (6) in the flexible container ('2J) are closed to prevent particles from flowing in. Fill the rubber bag container (2) with the ion exchange resin sufficiently. , small hole (7
) Swells and contracts as water and salt solutions enter and exit.

■) is a fastening thread, and old) is a fastening plug.

Holes are made in the plug 01) through which the tubes (5) and (6) pass, and the plug and both tubes are fixed. Although the thread (3) that restricts the longitudinal elongation of the bag (2) is not shown, it is necessary. Due to the swelling of each part, the container (2) swells in the radial direction and at the same time contracts slightly in the axial direction due to the restraint thread.For this reason, the tube (5),
It is more effective if the tip of (6) does not touch the stopper 01).

According to prototype experiments, dry ion exchange resin (DOWE
X1, Xi, 50-100mesh, 0.3g
) (outer diameter 41II of '2J)
! Ice water was injected or drained every minute, and the swelling equilibrium reached 9cm after 4 minutes.

Dry ion exchange resin (DOWEX 50W, X2.50
~100mesh) 7.8g was filled, 24 cotton threads were placed in a latex tube, and 4 fishing lines (for example, Higer (Unitika)) were wrapped around the outside of the tube. The tube was inserted into an intestine with an inner diameter of 18°C and a vinyl hose with an outer diameter of 21 mm, and an aspirator was used to discharge water using the vinyl hose as a model of a biological tract stenosis, and a swelling experiment was conducted by injecting water. After minutes it swelled to 26.3 inches. From this result, the swelling pressure (p) of the catheter was calculated based on the beam stress of the pressure vessel using p-2tσ/D (D is the vessel diameter, t is the vessel wall thickness, and σ is the beam stress). The pressure was p-7, 3 atm at the start of swelling, and p-4, 3 atm (both gauge pressures) at maximum swelling.

In addition, two types of dry ion exchange resins (DOWEX 50W% x 2.50 ~
100 mesh and DOWEX I SXi, 50-1
A total of 7.8 g of 00 mesh (weight ratio 4:1) was filled,
When a free swelling experiment was carried out using an aspirator, the outer diameter L5+u swelled to 27+m after 5 minutes, and 1N Na
24.8 m1 after 2 minutes by Cf, 2 by water injection again
8+mm.

It contracted to 24.5 mm after 7 minutes with 3N NaCf.

In addition, according to a swelling experiment in which another prototype identical to this catheter was inserted into the above-mentioned vinyl hose (tube stenosis model), the outer diameter of the vinyl hose was swollen from 21n+m to 25.5+m, and the swelling pressure was 6.2 atm. and 1 normal NaCf
24.8 mm by 3, 2 by NaCf
After 0 minutes, it was able to contract at 23.2 am.

The results of these prototype experiments indicate that DOW
EX 50W and This study also shows that it is effective to use an aspirator and to axially embed or wrap a flexible container (latex tube) with a high breaking strength thread to increase radial swelling.

Note that the mechanical work performed by a polymer gel (especially an ion exchange resin) is considered to be proportional to its weight, and can be expressed by the following formula.

pΔV kw (p is the swelling pressure, ΔV is the volume increase due to swelling, W is the weight of the ion exchange resin, and k is a constant having the dimension of length) From the above experiment, using the above formula k-2XIO5[Cm16 Therefore, mechanochemical catheters can be designed.

Strips of polyacrylic acid gel crosslinked with polyvinyl alcohol can be used instead of ion exchange resin particles, but the swelling rate will be slower.

Figure 6 shows the glass filter (4) in Figure 4 in a container (2).
Place the liquid drain pipe (
This is a liquid circulation type in which the tip of the filter (6) is embedded and the liquid that has soaked into the glass filter (4) is discharged using a syringe. The upper end of the container (2) consisting of a bag is closed with a thread (T) to prevent the filled powder of the water-absorbing polymer gel (1) from flowing out. The liquid injection tube (5) has a small hole [7].

An example of a prototype experiment of this device is described below. The liquid injection tube (5) and the liquid discharge tube (6) are Teflon tubes with an outer diameter of 1 ml, and the liquid injection tube (5a) and the liquid discharge tube (6a) are silicone tubes with an inner diameter of 1 mm and an outer diameter of 2 mm. The container (2) barrel bag is a latex tube with 4 threads embedded in the axial direction as a restraining member (3), and the container (2) barrel bag has an outer diameter of 5 mm and a length of 80 mm.
+u cylindrical shape. The water-absorbing polymer gel (1) made of ion exchange resin is DOWEX 1, Xi, 50-10
0mesh oThis resin granule is heated to 50℃ in a dryer at about 48℃.
After drying for an hour, 0.4 g of the product was filled into a barrel bag (container (2)). by injecting ICE of distilled water per minute.
II11 tubular container (2 swelled in the radial direction to 8 mm s after 2 minutes and 9111 m after 3 minutes.After 7 minutes, after draining the water with a syringe, 1 cc of 1N sodium chloride solution was injected per minute, and after 3 minutes Outer diameter is 7.5 fins, 711I1 after 4 minutes
It shrunk to 1.

If the outside diameter of the device is increased and the amount of resin particles is increased, the expansion of the outside diameter will further increase. When this device is inserted into a stenosis in a body canal, a swelling pressure will be generated against the stenosis that restricts the radial expansion of the device, causing the stenosis to expand.

Figure 7 shows a layer of water-absorbing polymer gel (8
) and water-absorbing polymer gel (1) made of ion exchange resin are alternately layered (formed by dipping), and the outermost layer is covered with a container (2) made of latex by dipping. Although the swelling speed is slower, the first to
It can be formed into a thinner catheter than that shown in Figure 6.

According to prototype experiments, both layers each have an outer diameter of 3.2 layers (4 layers in total).
A container (2) consisting of a 2 cm rubber tube was swollen to an outer diameter of m1 after 500 minutes by injecting 1 ce of water several times.

Figure 8 shows a water-absorbing polymer gel (1) with a homogeneous gel morphology made of a water-absorbing polymer or polyelectrolyte gel.
, a liquid injection tube (5) with a closed lower end, and the cylindrical gel (1).
) is a device consisting of a container (a) such as a bag.The liquid injection tube (5) is a hollow tube with a small hole (7).The container (2) such as a bag is made of latex. A water-permeable cloth such as a polymer membrane or gauze that blocks water.A container such as a bag (2J and the liquid injection tube (5) are tied with thread η (a fastener may be used). By injecting water from the top, dry gel (
1), the gel (1) swells in the radial direction of the container (2), such as a bag or tube, and is intended to widen the stenosis. Due to the rigidity of the liquid injection pipe (5),
Gel (1) cannot swell inward. In addition, the gel (1) can be extracted from the body using a container such as a thin film bag ('2J) that covers the gel (1). An outlet for air in the liquid injection tube (5) is required, and the liquid injection tube (5) can be removed from the body as shown in Figure 3A above. Alternatively, as shown in Figure 3B, if you make a double tube and inject from one side, it becomes a liquid circulation system.At the same time, the air in the tube and particles can be discharged.The container (2) such as a bag is made of cloth such as gauze. The swelling performance of the gel (1) will be better if it is moistened with water in advance and then inserted into the body.The swelling equilibrium time is determined by the thickness of the cylindrical gel (1) (
Since the swelling is proportional to the square of the radius), if the wall thickness is thick, it takes several hours to several tens of hours to reach swelling equilibrium. In Figure 8, the outer surface of the cylindrical gel (1) is attached to a container such as a bag ('
When covering with 2J to allow water to spread between the outer surface and the bag, the outer diameter of the dry gel of 3 mm is 1
After an hour, it swelled to 3.5 mm, and after 2 hours, it swelled to 3.8 mm.

From the results of this experiment, it is estimated that the swelling rate of the device described in Japanese Patent Publication No. 59-501345 is extremely slow, on the order of several hours.

For dilation of the urethra, it seems effective to slightly dilate the urethra with a metal bougie catheter and then use a thin mechanochemical catheter tube with an outer diameter of 3 to 4 tam. For anal enlargement, it is necessary to use a catheter tube with a large diameter. Thoroughly dried in a dryer (for example, 50
The trick to increasing the degree of swelling and swelling pressure is to pack as much of the ion exchange resin as possible in a contracted state with a 1-3 N sodium chloride solution into a bag. In the case shown in FIG. 7, the trick to increasing the swelling degree and swelling pressure is to dry the resin particles in the alternating layers with polyacrylic acid gel and water-absorbing polymer as much as possible, and to increase the ff1ffi as much as possible. In addition, the swelling rate of the mechanochemical/forced chichile can be adjusted by adjusting the amount of water injected and the frequency of injection. Another possible swollen gel is a mixture of ion exchange resin particles and polyacrylic acid gel.

1 to 8 are examples of the present invention, and the present invention means various combinations thereof.

The present invention is capable of achieving a swelling pressure of over 5 atmospheres by sufficiently filling a latex cylindrical bag with sufficiently dried ion exchange resin particles, and is judged to be superior to conventional air catheters in this respect. be done.

〔Effect of the invention〕

The mechanochemical catheter of the present invention achieves swelling equilibrium relatively quickly, on the order of minutes, and allows for external control of the swelling rate and amount, allowing for greater local swelling pressure than conventional air balloon catheters. Since the swelling rate is not rapid, it causes less pain to the patient, does not damage the application site, and has the advantage that the stenosis can be enlarged at will.

[Brief explanation of the drawing]

Figure 1 shows the configuration of a liquid-releasing mechanochemical catheter filled with ion exchange resin, and Figure 2 shows the configuration of a liquid circulation type mechanochemical catheter filled with powder (pieces) of ion exchange resin or polymer electrolyte gel. Figure, 3A-3
Figure B is a cross-sectional view of the liquid injection pipe that also serves as the liquid discharge pipe in Figure 2, and Figure ζ14 is the liquid circulation type 2 filled with ion exchange resin.
Figure 5 is a diagram showing the configuration of a liquid circulation type two-tube mechanochemical catheter filled with ion exchange resin, Figure 6 is a diagram showing the configuration of a mechanochemical catheter filled with ion exchange resin at the lower end of the container filled with ion exchange resin. A configuration diagram of another liquid circulation type two-tube mechanochemical catheter with a discharge tube placed inside the installed glass filter. Figure 7 shows a mechanochemical catheter with alternating ion exchange resin layers and polymer electrolyte gel layers. 8 shows a liquid circulation type mechanochemical catheter constructed solely of a cylindrical homogeneous water-absorbing polymer. (Main symbols in the drawing °) (1): Water-absorbing polymer gel (2): Container (3): Restraint member (4) Nigarasu filter (5): Liquid injection tube (5a): Liquid injection tube (6) ): Liquid discharge pipe (8a): Liquid discharge pipe (7); Small hole (8): Water-absorbing polymer gel layer (9); Partition plate 00): Fastening thread old): Fastening plug No. 1 decoy No. 2nd group

Claims (1)

[Claims] 1 A cylindrical or spindle-shaped catheter filled with a water-absorbing polymer gel in a stretchable flexible container,
A liquid injection pipe and a liquid discharge pipe are provided for injecting and circulating a liquid that swells the water-absorbing polymer gel from outside. A mechanochemical catheter used to widen a pathologically narrowed part of a canal or duct.