JP2003175111A - Epidural anesthesia catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epidural anesthesia catheter which can easily and surely confirm the position of the distal end of a catheter in an epidural cavity and which has small worsening of mounting feeling, small anxiety about a tissue damage and a safety even in the case of indwelling for a long period. <P>SOLUTION: This epidural anesthesia catheter comprises the catheter 1 having an opening 11 provided at the distal end, a catheter base 2 connected to the base end of the catheter 1, an energizing electrode stylet 3 inserted along a catheter cavity and made of a twisted metal wire and a Y tube-like stylet base 4 fixed by exposing the base end 31 of the stylet 3. In this catheter, the rear end of the base 2 and the distal end of the base 4 are detachable, and the stylet 3 is constituted in a structure in which the stylet 3 is insertable into and removable from the catheter 1 cavity. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter device for injecting a local anesthetic or an analgesic into an epidural space, and more specifically, to which position in the epidural space the liquid injection part at the tip of the catheter is located. An epidural anesthesia catheter that facilitates and ensures confirmation.

[0002]

2. Description of the Related Art Epidural anesthesia is a procedure for injecting an anesthetic or an analgesic into the epidural space outside the dura in the spinal canal. By indwelling the tip of a thin catheter (an epidural anesthesia catheter) and holding the proximal end of the catheter outside the body, a drug solution such as a local anesthetic can be injected into the epidural space through the catheter as many times as necessary. This is an anesthesia method that enables continuous analgesia not only during surgery but also after surgery, and is also suitable for chronic pain management in the pain clinic field. It is widely used as an excellent anesthesia method with few side effects.

However, in order to obtain an effective anesthetic effect with this epidural anesthesia catheter, it is an important point to make the tip hole portion of the catheter, which is the drug solution injection portion, reach an appropriate position in the epidural space. However, placement of this catheter in the epidural space is a blind procedure, so it is a difficult procedure that requires the operator's experience and intuition, and the position of the catheter inside the epidural space should be confirmed. Also, it is often done blindly and by actually observing the effect of anesthesia, and in many cases the anesthesia is not effective because it does not reach the appropriate position with a single placement procedure, so it is necessary to re-insert the catheter. For example, there is a problem in that the placement and confirmation of the position of the catheter is one of the factors that prolong the operation time. on the other hand,
As a means for ensuring this position confirmation, it is also attempted to grasp the catheter position by X-ray photography, but this method also takes time and burdens both the patient and the operator, including exposure to X-rays. There is a problem that becomes large.

Therefore, in order to solve the above problem, Japanese Patent Laid-Open No. 2001-8
A device has been proposed in 7391 in which a current-carrying wire and an electrode are arranged in a catheter, and the position of the tip of the catheter can be confirmed by supplying current to the catheter and applying electrical stimulation. This is because an opening is provided at the tip of a tube tube having an outer diameter of 0.3 to 1.5 mm, a tip electrode portion is provided on the surface of the lumen near the tip opening of the tube tube, and the outside of the rear end of the tube tube With a catheter for epidural anesthesia in which the rear end electrode part is arranged on the surface, and the front end electrode part and the rear end electrode part are connected by a fine current-carrying wire arranged along the longitudinal direction of the tube tube, When a small amount of physiological saline is ejected from the tip of the inserted tube and a weak electric current is applied to the physiological saline at that time, the physiological saline transmits electrical stimulation through the nerve roots and the body surface. Since a slight muscle contraction is caused or a hit feeling is perceived, the position of the tube tube can be accurately confirmed by these reaction positions and strengths.

[0005]

The above-mentioned catheter is an excellent one that enables easy and reliable confirmation of the position of the catheter tip in the epidural space. Since the electrodes are arranged at the ends and are connected by the current-carrying wire, the current-carrying wire is fixed to the catheter, and the metal wire is included in the catheter even during the indwelling period after the catheter is attached. It is unavoidable that the rigidity of the entire catheter will be higher than that of the catheter alone, and the epidural anesthesia catheter is often used by being left in the body for a long period of time. In addition, if the rigidity is high, there is an undeniable possibility that the tissue will be damaged by long-term placement. Further, in the above catheter, at least the tip side electrode needs to be provided on the inner surface of the catheter,
Since the electrode made of metal is always in contact with the chemical when injecting a chemical such as an anesthetic, it is feared that the electrode may undergo chemical changes such as corrosion, so it is safe even if a metal with excellent corrosiveness is used. Is not guaranteed. In particular, local anesthetics are more anxious because they are hydrochlorides that corrode metals.

Further, the above-mentioned catheter is complicated to manufacture by providing an electrode in the lumen of the catheter, and the parts cost and manufacturing cost are increased due to the step of embedding a thin metal wire inside the tube at the time of molding the tube. There is a problem that the product becomes expensive.

In view of the above problems, the present invention makes it possible to easily and surely confirm the position of the catheter tip portion to be placed in the epidural space during the operation of epidural anesthesia, and to provide long-term placement. It was an object to provide a safe epidural anesthesia catheter which does not cause a bad fit and has less anxiety such as tissue damage.

Further, it is an object to provide an epidural anesthesia catheter which has a simple structure and can greatly simplify the manufacturing process and has a low manufacturing cost while solving the above problems.

[0009]

In order to solve the above problems, an epidural anesthesia catheter of the present invention comprises a catheter having an opening at the distal end, and a catheter base connected to the proximal end of the catheter. From the vicinity of the catheter tip,
A metal current-carrying electrode stylet that is inserted along the lumen of the catheter, and a stylet base that fixes the electrode stylet by exposing the base end of the electrode stylet to the outside, The end portion and the base end portion of the stylet are detachable, and the electrode stylet is configured to be freely insertable into and removable from the lumen of the catheter.

The electrode stylet is composed of a stranded wire made of metal such as stainless steel.

Further, the stylet base is formed into a Y-shaped tube having an internal cavity communicating with one another, and one side of the bifurcated side is an electrolyte injection port and the other side is an electrode stylet fixing portion.

[0012]

According to the epidural anesthesia catheter of the present means, the tip position of the catheter in the epidural space can be confirmed easily and reliably by the following method. That is, after placing the electrode stylet on the catheter and placing it in the epidural space, a small amount of physiological saline is injected to the tip of the catheter to promote the flow of stimulation current, and the peripheral nerve stimulator ( The (+) pole and the proximal end of the electrode stylet exposed to the outside are connected with a lead wire, while the (-) pole of the peripheral nerve stimulator and the electrode attached to the buttocks are connected with a lead wire, and a weak current is applied to this. Then, since the nerve roots that act depend on the position of the tip of the catheter, the position of the tip of the catheter can be confirmed by the difference in the position of the contracting back muscle.

Further, since the electrode stylet can be inserted into and removed from the catheter, if the tip of the catheter is confirmed to be in an appropriate position, the electrode stylet is removed so that it can be left in the body for a long time. as,
Since the catheter is made of a flexible resin only, the rigidity during indwelling can be kept low and the possibility of damaging the tissue can be reduced. Further, by eliminating the metal portion in the chemical liquid passage, it is possible to eliminate inconvenience such as chemical change due to contact between the metal and the chemical liquid.

When the electrode stylet is twisted with a metal, by twisting an appropriate number of ultra-thin metal wires, the wire becomes more flexible than a metal wire having the same thickness as the twisted wire, and the rigidity of the catheter is suppressed to a low level. Therefore, it is possible to reduce the burden and risk when inserting the catheter.

Further, the stylet base has a Y-tube shape, one end of the bifurcated side is a physiological saline supply port, and the other is a fixed portion of the electrode stylet, and the tip end of the stylet base is formed. Since the rear end of the catheter base and the catheter base are detachable, the device can be adapted to the above-mentioned usage. During the indwelling, unnecessary parts can be removed and only the catheter and catheter base necessary for injecting the drug solution can be removed. You can leave.

Further, since the structure is basically constituted only by connecting the catheter base to the catheter and inserting the electrode stylet connected to the stylet base into the lumen, the conventional electrode catheter described above is very simple. Compared with, the manufacturing process can be greatly simplified.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an epidural anesthesia catheter of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the overall construction of the epidural anesthesia catheter of the present invention. The epidural anesthesia catheter of this example is
Basically, a catheter 1 and a catheter base 2 connected to the proximal end of the catheter 1, an electrode stylet 3 inserted into the lumen of the catheter, and a stylet base 4 connected to the proximal end of the electrode stylet Composed. Explaining the respective coupling states, the catheter 1 and the catheter base 2 are connected by inserting the proximal end portion of the catheter 1 from the front end portion of the catheter base 2 and further tightening ring 22 inside the catheter base 2 described later in FIG. The through hole 221 is inserted into the through hole 221 and the tightening adapter 23 of the catheter base 2 is tightened, whereby the diameter of the through hole 221 of the tightening ring 22 is narrowed and the connection is held. On the other hand, the electrode stylet 3 and the stylet base 4 are connected by inserting the base end of the electrode stylet 3 from the front end of the stylet base 4 and branching the stylet base 4 into a Y-shape. Fixed part 4
On one side, a part of the base end portion of the electrode stylet 3 is exposed to the outside of the stylet base 4, and the exposed base end portion is left outside, and a stylet fixing cap 44 is attached to the electrode stylet fixing portion 41. Fix and connect. Further, the catheter 1 and the electrode stylet 3 are attached by inserting the electrode stylet 3 into the lumen of the catheter 1 and inserting the female taper portion 24 (FIG. 3) at the rear end portion of the catheter base 2 and the front end portion of the stylet base 4. Although the male taper portion 43 is inserted and fitted, the tip of the electrode stylet 3 is made to have a tip in consideration of the safety of inserting the catheter 1 into the body and the effect of searching the catheter position by electrical stimulation. It is important to configure the length so that it is positioned within the catheter 1 by about 1 to 3 mm from the opening at the tip of the catheter 1. Naturally, the taper 24, 43 of the fitting portion between the catheter base 2 and the stylet base 4
Is detachable, and the electrode stylet 3 is detachable from the catheter 1 in association with the detachment.

FIG. 2 shows the tip side of the epidural anesthesia catheter of the embodiment of the present invention, and FIG. 3 shows the base side. Less than,
Details of each part will be described. The catheter 1 is made of a flexible resin such as polyethylene or fluororesin, and is made of a non-toxic resin considering long-term placement in the body and has an outer diameter of 0.8 mm and a length of about 950 mm. The opening at the tip portion, which is the equivalent chemical solution injecting portion, is configured as an open-end opening 11 having only the tip portion opened. This is because when confirming the position of the catheter by electrical stimulation, it is considered that more accurate position confirmation is possible compared to the side hole type when the end is open, that is, it is often used as the epidural anesthesia catheter tip. This is because if the tip portion is closed and a plurality of side holes are provided, the current flow may be dispersed during electrical stimulation, which may not be suitable for accurate position confirmation. In addition, graduations 12 which are indexes of the insertion length generally attached to this type of catheter are provided at appropriate intervals. In the present embodiment, the electrode stylet 3 is capable of conducting electricity effectively for electrical stimulation, is highly flexible, and suppresses rigidity as low as possible. In the present embodiment, three thin wires of stainless steel of about 0.1 mm are twisted together. Using the stranded wire formed as described above, the entire outer diameter was set to about 0.24 mm, and the length was set to be about 2 mm shorter than the tip of the catheter when inserted into the lumen of the catheter 1 as described above. In addition, the proximal end portion 31 exposed to the outside of the stylet base 4 described above is a clip (not shown) at the tip of a lead wire that is connected to a nerve stimulator (not shown) by a lead wire (not shown). Therefore, the connection is formed in a reliable ring shape. The catheter base 2 includes an adapter body 21, a tightening ring 22, and a tightening adapter 2.
3, the adapter body 21 and the tightening adapter 23 are made of a hard resin, and the screw part at the rear end of the adapter body 21 and the screw part at the front end of the tightening adapter 23 are connected and used together. Has a rubber elasticity and is made of a resin formed in a ring shape by providing a through hole 221 for inserting a catheter in the center,
It is inserted and configured so as to be sandwiched between the adapter body 21 and the tightening adapter 23, and the screw portion of the adapter body 21 and the screw portion of the tightening adapter 23 are strongly tightened to each other to be inserted inside. The tightening ring 22 is crushed to reduce the inner diameter of the through hole 221 and loosen the tightening to increase the diameter of the through hole 221. As a result, when the catheter 1 is inserted into the through hole 221, the tightening adapter 23 is tightened to a certain degree so that the through hole 2
21 is tightened and the catheter 1 is connected and fixed, and by further tightening, the through hole 221 is further tightened to close the lumen of the catheter 1, and conversely by loosening it, the through hole 221 is opened and the catheter lumen is opened. Is possible.
Naturally, the catheter 1 is handled such that it is loosened and opened when injecting a drug solution, and clamped and closed when not in use.
Further, the rear end of the tightening adapter 23, which is the rear end of the catheter base 2, serves as a connection part with the stylet base 4,
The female taper 24 is formed to serve as a drug solution supply port for anesthesia or the like, and is provided with a protective cap 25 that closes the opening when not in use to keep the drug solution supply port clean.
The stylet base 4 is formed as a hollow resin molded product formed in a Y-tube shape, and a front end portion which is a connection portion with the catheter base 2 has a male taper 43 shape.
As a detachable type, one of the Y-shaped rear end portions is provided with a fixing cap 44 for holding and fixing the electrode stylet at the end as the electrode stylet fixing portion 41 described above, and the other is provided with physiological saline. The mouth 42 is formed by forming a female taper.

Next, the clinical use of the epidural anesthesia catheter of the present invention will be described in detail. 1. A state in which an epidural puncture needle (not shown) is punctured from the skin to the epidural space and the epidural anesthesia catheter of the present invention is attached to the electrode stylet 2 through the lumen of the epidural puncture needle. To advance about 50 mm into the epidural space. 2. A small amount of physiological saline is injected from the electrolyte solution supply port 42 of the stylet base 4 in order to promote the flow of stimulation current to the nerve. 3. The (+) pole of the peripheral nerve stimulator and the proximal end portion 31 of the stylet 3 exposed to the outside are connected by a lead wire. 4. On the other hand, the (-) pole of the peripheral nerve stimulating device and an electrode (not shown) for electrocardiogram etc. attached to the buttocks in advance are connected by a lead wire. 5. Turn on the peripheral nerve stimulator and gradually increase the output. 6. The patient is observed and the tip of the electrode stylet 3, that is, the tip of the catheter 1 is confirmed by the position of the contracting back muscle. 7. The same electrical stimulation operation is repeated until the catheter 1 can be guided to the target position. 8. When the tip of the catheter 1 can be guided to the target position,
The electrode stylet 3 is removed together with the stylet base 4, and a chemical solution such as anesthesia is injected from the rear end of the catheter base 2 to start anesthesia.

[0021]

EFFECTS OF THE INVENTION According to the present invention, the catheter tip position can be easily and surely confirmed by electrical stimulation due to the above-mentioned action, so that the placement of the catheter at the proper position of the epidural space depends on experience and intuition. In addition, the epidural reduces the burden on both the patient and the surgeon because it eliminates the need for time-consuming and tedious work such as X-ray photography for position confirmation and catheter reinsertion in the event of a malfunction. An anesthesia catheter can be provided.

Further, after confirming the catheter position by the above-mentioned electrical stimulation, the electrode stylet is removed, and only the catheter is kept indwelling during the indwelling, and the rigidity is kept low. It is possible to reduce the possibility of damage to the tissue, and because the metal part such as the electrode does not remain in the catheter lumen due to the same action, there is no fear of trouble due to contact between metal and drug solution. It is possible to provide an epidural anesthesia catheter that is safe and highly safe for both patients and operators. Furthermore, by using the electrode stylet as a twisted wire of a thin metal wire, it is possible to make the epidural anesthesia catheter safer and more secure because of the effect of reducing the rigidity when the catheter is inserted.

Further, as described above, the structure is easy and the manufacturing process can be greatly simplified, so that it is possible to provide an inexpensive epidural anesthesia catheter having the above-mentioned effects and high performance. .

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an epidural anesthesia catheter of the present invention.

FIG. 2 is a configuration diagram showing a catheter tip portion according to an embodiment of the present invention.

FIG. 3 is a configuration diagram showing a base portion according to the embodiment of the present invention.

[Explanation of symbols] 1. catheter 11. Aperture 12. scale 2. Catheter base 21. Adapter body 22. Tightening ring 221. Through hole 23. Tightening adapter 24. Female taper part 25. Protective cap 3. Electrode stylet 31. Electrode stylet base end 4. Stylet base 41. Stylet fixing part 42. Saline supply port 43. Male taper 44. Fixed cap

Claims (3)

[Claims] 1. A catheter having an opening at its tip,
A catheter base connected to the proximal end of the catheter, a metal current-carrying electrode stylet inserted along the catheter lumen from near the catheter tip, and an electrode stylet at the proximal end of the electrode stylet. It is characterized in that it is configured by a stylet base that is exposed and fixed to the outside, the catheter base rear end and the stylet base tip are detachable, and the electrode stylet can be freely inserted into and removed from the catheter lumen. And an epidural anesthesia catheter. 2. The epidural anesthesia catheter according to claim 1, wherein the electrode stylet comprises a metal strand. 3. The stylet base is formed in a Y-shape having a lumen communicating with it, one side of the bifurcated side being an electrolyte solution supply port, and the other side being an electrode stylet fixing part.
Alternatively, the epidural anesthesia catheter according to claim 2.