Self-retaining catheter and inserting apparatus thereof

In a self-retaining catheter in which a leading end of the catheter can be fixed to an inner wall of a tubular organ such as a blood vessel, a wire with higher stiffness than a catheter body and in a winding shape greater than an outside diameter of the catheter body is mounted inside a leading end of the catheter body or in a projecting state from the leading end of the catheter body. An aperture of a slit shape is formed in a peripheral wall of the catheter body, in order to allow a medical fluid to flow out therethrough. A self-retaining catheter inserting apparatus includes the above-stated self-retaining catheter, a core wire arranged to be inserted into and withdrawn from the self-retaining catheter, a master catheter through which the self-retaining catheter can pass, and a sheath necessary for the master catheter to be inserted into a tubular organ, and preferably, the apparatus further includes a medical fluid injection port.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a self-retaining catheter that is arranged 
to be retained in a blood vessel or the like of a patient and to permit a 
medical fluid, for example such as a carcinostatic, to be injected on a 
periodic basis, and an inserting apparatus thereof. 
2. Related Background Art 
For administration of such a medical fluid as a carcinostatic, for example, 
the medical fluid was administered into a blood vessel conventionally by 
use of an injection syringe or a drip. In that case, the medical fluid 
circulated through blood vessels in the body, and thus there was the fear 
of damaging the normal cells in addition to cancerous cells. 
Under such circumstances, attempts have been made to achieve such 
techniques as to percutaneously insert a catheter into a blood vessel, 
locate the leading end of this catheter at an arterial inlet to an organ 
affected by cancer, and directly inject the medical fluid into the organ 
affected by cancer, thereby accomplishing a prominent carcinostatic effect 
even with a small dose of the medical fluid. 
In this case, after the catheter was set so that the leading end thereof 
was located at the arterial inlet to the target organ, injection of the 
medical fluid was carried out while the base side of the catheter was 
fixed to the patient's body so as to prevent the leading end of the 
catheter from shifting from the position. 
In order to prevent the medical fluid from flowing into arteries branched 
to the other normal organs, embolization coils or the like were inserted 
into inlets of the arteries branched to the other normal organs so as to 
temporarily obstruct the blood flow, so that the medical fluid could flow 
into only the organ affected by cancer. 
On the other hand, there are conventionally known catheters having the 
structure capable of retaining themselves not only in the blood vessels, 
but also in tubular organs of the human body, and an example of such 
catheters is the one described in Japanese Patent Application Laid-open 
No. 5-192389, in which the catheter is comprised of an outside tube, an 
inside tube, and a reinforcement interposed between them, and in which a 
flap projecting to engage an inner wall of a tubular organ of the human 
body is mounted on the periphery of the leading end of the outside tube. 
Another known example is the one described in Japanese Utility Model 
Application Laid-open No. 5-86355, in which a plurality of fins are 
arranged at intervals on the periphery of the leading end or an 
intermediate section of the catheter so as to act as a cushion, a seal, a 
stopper, and a protector. 
In treatments by the conventional method for locating the leading end of 
the catheter at the inlet of the artery to the affected organ as a target 
and directly feeding the medical fluid into the target organ, there 
sometimes occurred, however, accidents that the position of the leading 
end of the catheter shifted because of a body motion, such as tossing, of 
the patient on the occasion of injection of the medical fluid, so as to 
cause the medical fluid to flow into the other organs than the target 
organ, though the base side of the catheter was fixed to the patient's 
body. 
Further, it was not easy to apply the self-retaining catheter described in 
Japanese Patent Application Laid-open No. 5-192389 to a tubular organ 
comprised of a narrow and thin wall, such as a blood vessel, because the 
flap projecting from the periphery of the leading end of the catheter 
tended to damage the internal wall of the tubular organ. 
With the self-retaining catheter described in Japanese Utility Model 
Application Laid-open No. 5-86355, the fins also tended to damage the 
internal wall of the tubular organ and in applications to the blood 
vessels or the like, it was difficult to retain the catheter over the long 
term, because the fins obstructed the blood flow. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a self-retaining catheter 
whose leading end can be fixed to an inner wall of a tubular organ such as 
a blood vessel, that causes little damage to the inner wall of the tubular 
organ during insertion and during withdrawal, and that causes little 
obstruction against the blood flow or the like in the self-retaining 
state, and also to provide an inserting apparatus of the self-retaining 
catheter. 
In order to accomplish the above object, a self-retaining catheter 
according to the present invention comprises a tubular catheter body, and 
an elastic wire of a winding shape buried in one end portion of the 
catheter body, wherein the end portion of the catheter body with the wire 
inside is in a winding state. 
In this structure, when the leading end of the self-retaining catheter is 
guided to a target portion of a tubular organ such as a blood vessel to be 
retained there, the catheter body starts to go back into the winding state 
because of the wire buried inside the leading end of the catheter body, 
whereby the catheter body is fixed while being elastically urged against 
the inner wall of the tubular organ. In this case there occurs little 
damage to the inner wall of the tubular organ, because the catheter body 
is fixed while being urged against the inner wall of the tubular organ by 
the winding shape of the catheter body, different from the structures 
wherein the flap or fins projecting from the catheter engage the inner 
wall of the tubular organ. Since the catheter body is in the winding 
state, a clearance is created between the catheter body and the inner wall 
of the tubular organ, so that the catheter does not obstruct the blood 
flow or the like. 
When the self-retaining catheter is withdrawn, a master catheter is 
inserted along the periphery of the self-retaining catheter. Then the 
self-retaining catheter is pulled to the base side relative to the master 
catheter, so as to retract the self-retaining catheter into the master 
catheter while stretching the leading end of the self-retaining catheter. 
This simple operation permits the self-retaining catheter to be withdrawn, 
and thus the withdrawal (evulsion) of the self-retaining catheter can be 
performed readily. 
Another embodiment of the self-retaining catheter according to the present 
invention comprises a tubular catheter body, and an elastic wire of a 
winding shape greater than an outside diameter of the catheter body, 
wherein said wire is connected to one end of the catheter body so as to 
project outwardly from the catheter body. 
In this structure, when the leading end of the self-retaining catheter is 
guided to a target portion of the tubular organ such as the blood vessel 
to be retained there, the wire connected to the leading end of the 
catheter body starts to go back into the winding state, so that the wire 
becomes fixed while being elastically urged against the inner wall of the 
tubular organ. Therefore, the self-retaining catheter causes little damage 
to the inner wall of the tubular organ and does not obstruct the blood 
flow or the like, from the same reasons as described above. 
The catheter can be constructed in such a structure that the catheter body 
linearly extends from a position in a periphery of the winding shape of 
the wire. 
In this structure, when the leading end of the catheter body is fixed 
inside the tubular organ such as the blood vessel, the base side of the 
catheter body extends from the position in the periphery of the winding 
shape of the leading end and along the inner wall of the tubular organ. 
Therefore, this structure causes little obstruction to flow of the body 
fluid such as the blood flow and can prevent occurrence of a thrombus or 
the like. 
The catheter can be constructed in such a structure that an aperture for 
outflow of a medical fluid is formed in a peripheral wall of the catheter 
body near the end where the wire is mounted, the aperture is formed in a 
slit shape, the aperture is opened when a pressure of the fluid inside is 
applied thereto, and the aperture is closed when the pressure of the fluid 
inside is not applied thereto. 
In this structure, after the medical fluid flows in the axial direction 
inside the catheter body, the medical fluid changes its direction so as to 
flow sideways out of the aperture formed in the peripheral wall. This 
restrains the medical fluid from hitting the inner wall of the tubular 
organ such as the blood vessel with strong force and in turn, it can avoid 
obstruction of a flow passage or the like due to the damage to the inner 
wall of the blood vessel or the like. Since the aperture is of the slit 
shape and is opened only when the pressure of the fluid inside is applied 
thereto, the body fluid such as the blood can be prevented from flowing 
back through the catheter during the periods in which the medical fluid is 
not injected. 
In the conventional methods, the medical fluid introduced into the catheter 
advanced along the axis of the catheter and flowed straight out of the 
leading end thereof. Thus the conventional methods had the problem that 
the medical fluid hit the inner wall of the blood vessel, the blood vessel 
absorbed the medical fluid, it damaged the inner wall of the blood vessel, 
and it was likely to cause obstruction in the blood vessel. In the present 
invention, where the aperture for outflow of the medical fluid is formed 
in the peripheral wall of the catheter body, the medical fluid is, 
however, prevented from directly hitting the inner wall of the blood 
vessel or the like with strong force, which can prevent the obstruction 
due to the damage to the inner wall of the blood vessel or the like. 
The self-retaining catheter can be constructed in such a structure that an 
aperture for outflow of the medical fluid is formed in a peripheral wall 
of the catheter body near the end where the wire is mounted and that the 
aperture is formed as being directed toward the center of the winding 
shape of the wire, in the peripheral wall of the catheter body. 
In this structure, where the aperture of the catheter body is directed 
toward the center of the winding shape of the wire, i.e., inwardly inside 
the tubular organ, the medical fluid is prevented from strongly hitting 
the inner wall of the tubular organ, because the aperture is directed 
toward the center of the tubular organ. Thus there occurs little damage to 
the inner wall. 
The self-retaining catheter can be constructed in such a structure that a 
contrast chip is mounted near the aperture of the catheter body. 
In this structure, where the contrast chip is mounted near the aperture of 
the catheter body, a position of the medical fluid injection aperture can 
be detected with accuracy, and the medical treatment can be carried out 
more precisely. 
A self-retaining catheter inserting apparatus according to the present 
invention comprises the self-retaining catheter according to the present 
invention, a core wire arranged to be detachably inserted into the 
self-retaining catheter, and a master catheter having an inside diameter 
that permits insertion of the self-retaining catheter. 
In this structure, the self-retaining catheter can be guided to a 
predetermined portion in a tubular organ through the master catheter, and 
the self-retaining catheter can be fixed in the tubular organ by restoring 
force of the wire when the leading end of the self-retaining catheter is 
made to project out of the master catheter. In this case, the insertion 
operation of the self-retaining catheter can be facilitated with increase 
in the stiffness thereof by inserting the core wire into the 
self-retaining catheter. 
Another embodiment of the self-retaining catheter inserting apparatus 
according to the present invention comprises the self-retaining catheter 
according to the present invention, a core wire arranged to be detachably 
inserted into this self-retaining catheter, a master catheter having an 
inside diameter that permits insertion of the self-retaining catheter, and 
a sheath for percutaneous insertion of the master catheter into a blood 
vessel. 
In this structure, the sheath is first percutaneously inserted into the 
blood vessel, the master catheter is then inserted through this sheath, 
the leading end of this master catheter is guided to a desired portion in 
the blood vessel, and the self-retaining catheter is inserted through this 
master catheter. Therefore, the insertion operation of the self-retaining 
catheter into the blood vessel can be performed surely and readily. 
A further embodiment of the self-retaining catheter inserting apparatus 
according to the present invention comprises the self-retaining catheter 
according to the present invention, a core wire arranged to be detachably 
inserted into the self-retaining catheter, a master catheter having an 
inside diameter that permits insertion of the self-retaining catheter, a 
sheath for percutaneous insertion of the master catheter into a blood 
vessel, and a medical fluid injection port to be embedded in the body 
while being connected to a base end of the self-retaining catheter. 
In this structure, the sheath is first percutaneously inserted into the 
blood vessel, the master catheter is then inserted through this sheath, 
and the leading end of this master catheter is guided to a desired portion 
in the blood vessel. Thereafter the self-retaining catheter is inserted 
through the master catheter, and the leading end of the self-retaining 
catheter is made to project out of the master catheter to be fixed to the 
inner wall of the blood vessel. Then the master catheter is drawn out, the 
medical fluid injection port is connected to the base end of the 
self-retaining catheter, and this medical fluid injection port is embedded 
under the skin. By this structure, an injection needle can be stuck into 
the medical fluid injection port when necessary and the medical fluid can 
be injected readily into the affected region of the target, which 
extremely reduces the load on the patient. 
When the self-retaining catheter is withdrawn, the master catheter is 
inserted along the periphery of the self-retaining catheter. Then the 
self-retaining catheter is pulled to the base side relative to the master 
catheter, so as to retract the self-retaining catheter into the master 
catheter while stretching the leading end of the self-retaining catheter. 
This simple operation permits the self-retaining catheter to be withdrawn, 
and thus the withdrawal (evulsion) of the self-retaining catheter can be 
performed readily.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 illustrates an embodiment of the self-retaining catheter according 
to the present invention. 
This self-retaining catheter 10 has a tubular catheter body 11, for 
example, made of a synthetic resin such as urethane, nylon, polyethylene, 
polypropylene, or silicone, or a shape memory alloy, or the like. A 
closure 13, which permits a core wire 12 to be inserted in a sealed state 
into the catheter body 11, is mounted at the base end of the catheter body 
11. The core wire 12 can be selected from wires of shape memory alloys, 
stainless steel, or the like, guide wires, and so on. 
The inside and/or the outside of the catheter body is preferably coated 
with a hydrophilic resin in order to enhance a sliding property of the 
core wire 12 to the catheter body 11 or in order to increase a sliding 
property of the catheter body 11 to a master catheter described 
hereinafter. 
A coil wire 14 having higher stiffness than the catheter body 11 is buried 
inside the leading end of the catheter body 11. The wire 14 is made of a 
shape memory alloy treated by such a shape memory treatment as to exhibit 
superelasticity near body temperatures of the human body in the case of 
this embodiment, but the wire 14 may also be selected from wires of other 
metals such as stainless steel, wires of FRP with high stiffness, and so 
on. An outside diameter of the coil wire 14 in a free state is a diameter 
sufficiently larger than an inside diameter A of a self-retaining portion 
such as an objective blood vessel (see FIG. 11A). In the state in which 
the coil wire 14 is interpolated in the catheter body 11, the catheter 
body 11 is also in a winding shape like a coil having an outside diameter 
B larger than the inside diameter A of the self-retaining portion. Since 
the wire 14 has superelasticity while the catheter body 11 is made of a 
plastic pipe, they can be elastically deformed, so that they can be put 
inside an inside diameter C of the master catheter 51 (see FIG. 11A). In 
this state they can be inserted into a blood vessel or the like. A ring 
contrast chip 20 is mounted at the leading end of the catheter body 11. 
As shown in FIG. 2, the leading end of the wire 14 is fixed inside the 
catheter body 11 with an adhesive 15. This prevents the wire 14 from 
moving inside the catheter body 11. A distance a between the tip of the 
fixing part of wire 14 and the tip of the catheter body 11 is preferably 
5-50 mm and most preferably about 20 mm. This range provides the leading 
end of the catheter body 11 with flexibility and thus prevents the leading 
end from damaging the inner wall of the blood vessel or the like. The size 
of the catheter body 11 may be properly determined depending upon an 
applied object, but, for example in the case of those for liver arteries 
of adults, the outside diameter b is preferably 0.3-2 mm and the inside 
diameter c is preferably 0.1-1.7 mm. 
FIGS. 3A to 3C show other examples of the fixing structure of the leading 
end of wire 14. 
In the example of FIG. 3A, a coil 16 is disposed around the periphery of 
the leading end of the wire 14, and the adhesive 15 is deposited so as to 
bury the coil 16 and the leading end of the wire 14, whereby the leading 
end of the wire 14 is fixed to the catheter body 11. In this example the 
coil 16 makes it easier to deposit the adhesive 15 and reduces the 
clearance between the wire 14 and the inner wall of the catheter body 11, 
so as to enhance the fixing strength. 
In the example of FIG. 3B, a contrast chip 17 having a ring shape or a 
C-shaped cross section is put inside the catheter body 11, the leading end 
of the wire 14 is put in this contrast chip 17, and the leading end of the 
wire 14 is fixed by caulking of the contrast chip 17. 
In the example of FIG. 3C, a contrast chip 18 having a ring shape or a 
C-shaped cross section is mounted on the periphery of the leading end of 
the catheter body 11, and the leading end of the wire 14 is fastened 
through the catheter body 11 by caulking of this contrast chip 18. 
As shown in FIG. 1 and FIG. 4, an aperture 21 of a slit shape is formed in 
a peripheral wall a distance d apart from the base end of the wire 14 in 
the catheter body 11 to the base of the catheter body 11. The length of d 
is suitably set depending upon an applied portion, but it is normally 1-15 
cm. When a pressure of a fluid is applied inside, the aperture 21 is 
opened as shown by the dotted line in FIG. 4. When the pressure of the 
fluid is not applied inside, the aperture 21 is closed. By this structure, 
the aperture is opened on the occasion of injection of a medical fluid, 
and during the other periods the body fluid such as the blood is prevented 
from flowing through the aperture 21 into the catheter body 11. 
In an alternative way, the self-retaining catheters may be supplied in a 
selling form without the aperture 21, and the aperture 21 of the slit 
shape may be formed depending upon patient's conditions, for example by 
urging the tip of a knife or the like against the peripheral wall of the 
catheter body 11 to cut it immediately before an operation. The aperture 
21 can be suitably formed by such working as to cut the wall with a knife 
or an edged tool having a fine edge. If the aperture 21 were made, for 
example, by machining with a grinder or the like, a part of the wall would 
be lost, so as to form an aperture always open. Therefore, the valve 
effect (the effect that the aperture is opened only when the pressure of 
the fluid is applied inside) would not be achieved well. 
FIGS. 5A to 5D show other examples of the aperture. 
In the example of FIG. 5A an aperture 22 is formed in a predetermined 
width. In the example of FIG. 5B an aperture 23 is formed in a 
predetermined width and is tapered at the both ends 23a, 23b. In the 
example of FIG. 5C a contrast chip 19 having a C-shaped cross section is 
mounted so as not to cover the aperture 21, on the periphery of the 
portion of the catheter body 11 where the aperture 21 is present, whereby 
the contrast chip 19 prevents the catheter body 11 from being crushed in 
the portion of aperture 21. In the example of FIG. 5D a contrast chip 19 
also having a C-shaped cross section is set so as not to close the 
aperture 21, on the inside surface of the portion where the aperture 21 is 
formed in the catheter body 11, whereby the contrast chip 19 prevents the 
catheter body 11 from being crushed in that portion. 
FIG. 6 is a perspective view to show an enlarged view of the leading end of 
the self-retaining catheter 10. 
The leading end of the self-retaining catheter 10 is kept in the winding 
state of the coil shape by the wire 14 (not illustrated in FIG. 6) 
disposed inside the catheter body 11 as long as no external force is 
exerted thereon. The base side of the catheter body 11 linearly extends 
from a position in a periphery of this coil winding portion. Because of 
this shape, when the self-retaining catheter is set in a tubular organ 
such as a blood vessel, the base side of the catheter body 11 extends 
along the inner wall of the tubular organ and thus is arranged so as not 
to be positioned in the center of the lumen of the tubular organ. 
The aperture 21 formed in the peripheral wall of the catheter body 11 is 
open while being directed in the direction A toward the center of the coil 
winding portion. This allows the aperture 21 to be directed inwardly of 
the tubular organ when the catheter is inserted into the tubular organ 
such as the blood vessel. This structure is free of the problem that when 
the medical fluid is allowed to flow through the aperture 21, the medical 
fluid is ejected strongly against the intima of the tubular organ to be 
directly absorbed through the intima, or the aperture is pushed against 
the intima of the tubular organ to interfere ejection of the medical 
fluid. 
While the contrast chip 20 is provided at the leading end of the catheter 
body 11, another contrast chip 20' may also be mounted near the aperture 
21 in place of this contrast chip 20 or together with the contrast chip 
20. This allows the position of the aperture through which the medical 
fluid is ejected, to be detected more accurately. These contrast chips 20, 
20' may also be located in the catheter body 11. 
The aperture 21' may be formed on the inside of the winding portion of the 
spiral shape, instead of the aperture 21 formed in the straight portion of 
the catheter body 11. In this case the medical fluid is introduced through 
the clearance between the internal surface of the catheter body 11 and the 
wire 14 to the spirally winding portion of the catheter body 11 to flow 
out through the aperture 21'. 
FIG. 7 illustrates the relation between the wire 14 and the core wire 12 in 
the self-retaining catheter 10. As illustrated, the base end of the wire 
14 extends toward the base of the catheter body 11, and the leading end of 
the core wire 12 extends toward the tip of the catheter body 11 and has 
such a thickness as to abut against the base end of the wire 14. This 
structure allows a pushing force to be occur in the self-retaining 
catheter 10 when the core wire 12 is forced into the catheter body 11. 
FIG. 8 illustrates another embodiment of the self-retaining catheter 
according to the present invention. Substantially identical portions to 
those in the embodiment shown in FIG. 1 will be denoted by the same 
reference numerals and the description thereof will be omitted herein. 
In the self-retaining catheter 30 of this embodiment a swirl of wire 32 is 
put inside the leading end of the catheter body 11 and the leading end of 
the wire 32 is fixed to the catheter body 11 with the adhesive 15. As a 
result, the catheter body 11 is kept in a swirl shape by the stiffness of 
the wire 32 as long as no external force is exerted thereon. In the case 
of this embodiment the base side of the catheter body 11 also linearly 
extends from the periphery of the swirl winding portion and the aperture 
20 is open as directed toward the center of the winding portion. As 
described above, a variety of shapes can be employed for the winding shape 
of the wire. 
FIG. 9 illustrates still another embodiment of the self-retaining catheter 
according to the present invention. 
In the self-retaining catheter 40 of this embodiment one end of wire 41 of 
a coil shape is connected to the leading end of the catheter body 11 and 
the wire 41 projects out of the catheter body 11. The diameter of the coil 
of wire 41 is larger than the outside diameter of the catheter body 11 and 
a contrast chip 42 is formed at the tip of the wire 41 by melting the wire 
in a ball shape or by welding a metal not transmitting X-rays, such as 
platinum or a platinum alloy, to the tip. This contrast chip 42 also 
presents the effect of preventing the inner wall of the tubular organ from 
being damaged. The outside surface of the wire 41 is preferably coated 
with an organism-compatible resin. 
The base end of the wire 41 is formed in a small coil shape, put in the 
catheter body 11, and fixed thereto with the adhesive 15. In the case of 
this embodiment the base side of the catheter body 11 also linearly 
extends from the periphery of the wire 41 of the coil shape and the 
aperture 21 formed in the peripheral wall of the catheter body 11 is open 
as being directed to the center of the coil shape of the wire 41. As in 
this embodiment, the wire as a fixing means to the tubular organ may 
project outwardly from the catheter body 11. 
Next, a method for administering a carcinostatic to liver arteries by use 
of the self-retaining catheter 10 shown in FIG. 1 will be described 
referring to FIG. 10 to FIG. 15. 
FIG. 10 is an explanatory drawing to show a state in which the 
self-retaining catheter 10 is percutaneously inserted into a blood vessel; 
FIGS. 11A to 11E are explanatory drawings to show procedures for inserting 
the self-retaining catheter 10 through the master catheter into the blood 
vessel and allowing the medical fluid to flow out; FIG. 12 is an 
explanatory drawing to show a state in which the leading end of the 
self-retaining catheter 10 is set at an objective portion of a blood 
vessel and fixed there; FIG. 13 is an explanatory drawing to schematically 
show an enlarged state in which the leading end of the self-retaining 
catheter 10 is set at the objective portion of the blood vessel and fixed 
there; FIG. 14 is an explanatory drawing to show a state in which the 
master catheter is withdrawn; FIG. 15 is a perspective view to show a 
medical fluid injection port; FIG. 16 is an explanatory drawing to show a 
state in which the medical fluid injection port is buried under the skin 
and in which the medical fluid is supplied thereto with an injection 
syringe. 
In FIG. 10, numeral 51 designates the skin and 52 a blood vessel (the 
femoral artery in this example). First, a sheath 53 is percutaneously 
inserted into the blood vessel 52 by the known Seldinger method. Then the 
master catheter 55 is inserted through a closure 54 provided at the base 
end of the sheath 53. Further, a guide wire not illustrated is inserted 
through a closure 56 provided at the base end of the master catheter 55. 
After the leading end of the guide wire reaches an objective portion of a 
blood vessel, the leading end of the master catheter 55 is forced ahead 
along the guide wire up to the aforementioned portion, and then the guide 
wire is pulled out. 
Then the self-retaining catheter 10 is inserted through the closure 56 
provided at the base end of the master catheter 55 and the core wire 12 is 
inserted through the closure 13 provided at the base end of the 
self-retaining catheter 10. Then the self-retaining catheter 10 is forced 
into the master catheter 55 while the stiffness is maintained by the core 
wire 12. For example, supposing the size of the sheath 53 is 5 Fr (French 
size), the size of the master catheter 55 is 4 Fr. 
As shown in FIG. 11A, the leading end of the self-retaining catheter 10 
inserted into the master catheter 55 passes in the master catheter 55 
while the coil wire 14 inside the catheter body 11 is stretched in a wave 
shape. 
When the master catheter 55 is pulled to project the leading end of the 
self-retaining catheter 10 out as shown in FIG. 11B, the leading end of 
the self-retaining catheter 10 elastically returns to the original coil 
diameter in the free state from the depressed state where it is limited to 
the inside diameter of the master catheter 55. Then the leading end of the 
self-retaining catheter 10 is elastically urged against the inner wall of 
the blood vessel 52. 
FIG. 11C shows a state in which the master catheter 55 is drawn out by the 
above operation and FIG. 11D shows a state in which the core wire 12 is 
pulled out and the medical fluid is injected into the self-retaining 
catheter 10 to flow out through the aperture 21. FIG. 11E is a sectional 
view along line e--e in FIG. 11D, which shows a state in which the medical 
fluid is flowing out toward the center of the blood vessel 52. 
In FIG. 12 and FIG. 13, 52a designates the right liver artery to which the 
carcinostatic is expected to be administered, 52b the left liver artery, 
52c the gastroduodenal artery, and 52d the splenic artery. It can also be 
contemplated that, prior to the administration of the carcinostatic, the 
embolization coils or the like are preliminarily inserted into blood 
vessels branched to normal organs to temporarily embolize those blood 
vessels so as to prevent the medical fluid containing the carcinostatic 
from flowing into the normal organs. In the case wherein the treatment 
continues over the long period while the self-retaining catheter 10 is 
buried in the body, it is, however, preferred to avoid the above 
embolization operation with the embolization coils while the aperture 21 
of the self-retaining catheter 10 is positioned as close to the affected 
part as possible. 
The leading end of the self-retaining catheter 10 is set, for example, in 
the right liver artery 52a to be fixed as being expanded by the restoring 
force of the wire 14 and being urged against the inner wall of the blood 
vessel in that portion. At this time the aperture 21 of the self-retaining 
catheter 10 is located at a branch point into the right liver artery 52a 
and the left liver artery 52b so that the medical fluid flowing through 
the aperture 21 can flow mainly in directions to the entire liver. Since 
the leading end of the self-retaining catheter 10 is fixed in the blood 
vessel, there is no possibility of a positional shift of the aperture 21 
even if the patient turns his body thereafter. 
After the leading end of the self-retaining catheter 10 is set at the 
objective portion as described above, the core wire 12 is withdrawn and 
the master catheter 55 is further withdrawn, thereby establishing the 
state in which only the self-retaining catheter 10 is put in the sheath 
53, as shown in FIG. 14. In this state the closure 54 of the sheath 53 and 
the closure 13 side of the self-retaining catheter 10 are disconnected, so 
as to project the self-retaining catheter 10 out from the base portion of 
the sheath 53. 
As shown in FIG. 15, the base portion of the self-retaining catheter 10 
thus cut is connected to a medical fluid outlet 62 of a medical fluid 
injection port 61. The medical fluid injection port 61 is constructed in 
such a structure that a container 63 having a truncated cone shape is made 
of a synthetic resin having a hardness too high for the injection needle 
or the like to pierce, a rubber film 64, through which the injection 
needle or the like can be stuck, is mounted in an aperture of the top 
surface of the container 63, and the aforementioned medical fluid outlet 
62 is formed in the side wall of the container 63. 
As shown in FIG. 16, after the skin 51 is incised, the medical fluid 
injection port 61 is buried inside the skin 51. At this time the base 
portion of the sheath 53 cut is fastened to the self-retaining catheter 10 
with thread 65 or the like, thereby preventing the blood from leaking from 
that portion. In this state the patient can live the daily life as being 
allowed to move freely. During that period, the catheter will not shift in 
the body, because the leading end of the self-retaining catheter 10 is 
fixed as shown in FIG. 12 and FIG. 13. 
For periodically administering the carcinostatic, the injection needle 71 
of the injection syringe 70 is stuck through the skin 51 into the rubber 
film 64 of the medical fluid injection port 61 and the medical fluid in 
which the carcinostatic is dissolved is injected into the medical fluid 
injection port 61. This medical fluid flows out of the medical fluid 
outlet 62 into the self-retaining catheter 10 and flows out through the 
aperture 21 of the self-retaining catheter 10. Then the medical fluid can 
be selectively injected into the liver affected by cancer. The medical 
fluid advances along the axis of the catheter in the self-retaining 
catheter 10 and then turns the direction to flow out sideways through the 
aperture 21 provided in the peripheral wall of the self-retaining catheter 
10. Therefore, the medical fluid is prevented from strongly hitting the 
inner wall of the blood vessel, and there is thus little damage to the 
inner wall of the blood vessel. 
It is also contemplated that a plurality of fine self-retaining catheters 
of about 1.5 Fr are simultaneously set through one blood vessel and are 
retained at different portions inside the human body. In this case, only 
medical fluids necessary for a plurality of organs can be simultaneously 
injected and administered to the respective organs; for example, a medical 
fluid A is administered to the liver arteries, a medical fluid B to the 
gastroduodenal artery, and a medical fluid C to the splenic artery. This 
can remarkably enhance the treatment effects on a patient suffering 
combined diseases and can decrease the treatment period.