Clip device

A clip device for a living tissue in a body cavity includes an introducing tube insertable into the body cavity. An operating member of the device is advanceably and retreatably inserted into the introducing tube; the operating member has a distal end portion. An operating wire is advanceably and retreatably inserted into the operating member, and the operating wire has a distal end portion and a retainer attached to the distal end portion of the operating wire. The clip device further includes a clip having a proximal end portion and a pair of arm portions extending from the proximal end portion and provided with a tendency to open. A clip squeezing ring is removably attached to the distal end portion of the operating member for closing the arm portions of the clip by fitting to the arm portions of the clip. And a coupling member is insertable into the clip squeezing ring, and the coupling ring is removably engaged with the retainer. The coupling ring further includes a hook portion to be engaged with the proximal end portion of the clip; holding member holds the coupling member inside the clip squeezing ring such that the coupling member can be removed from the clip squeezing ring when the operating wire is retreated. At least one of the arm portions is bent inward so as to be bow-shaped, and has an inner side provided with friction increasing the structure for increasing friction between the inner side of the arm portion and the living tissue.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a clip device used for hemostasis, marking, and 
ligation of a living tissue in a body cavity. 
2. Description of the Related Art 
Conventionally, a clip is introduced into a body cavity via an endoscope to 
grasp a living tissue of a body cavity for hemostasis, marking, and 
ligation, and the clip is left inside the body cavity. A device for such 
treatment is disclosed in, for example, Japanese Published Utility Model 
Application Publication No. Hei 4-26091. 
Japanese Published Utility Model Application Publication No. Hei 4-26091 
describes a clip device for grasping a living tissue. The clip device 
comprises a clip having a pair of grasping portions provided with a 
tendency to open; a clip squeezing ring for pulling in and closing the 
clip; and a coupling member insertable into the clip squeezing ring and 
provided with a deformable hook portion to be engaged with the clip. The 
clip and the coupling member are temporarily retained inside the clip 
squeezing ring by inserting them into the clip squeezing ring and filling 
a filler made of silicone. Further, the coupling member can be engaged 
with and disengaged from the main body of the device which has a guide 
tube insertable into a body cavity through an endoscope. 
Japanese Laid-Open Patent Application Publication No. Hei 5-212043 
discloses a clip device having a pair of grasping portions provided with a 
tendency to open, each of the grasping portions being provided in its 
middle with a bent portion bent outward in order to reduce the gap between 
the grasping portions. 
However, because the clip and the coupling member of the clip device 
disclosed in Japanese Published Utility Model Application Publication No. 
Hei 4-26091 are temporarily retained inside the clip squeezing ring by the 
filler, the force for fixing the members may vary in accordance with the 
state of filling the filler. Thus, the members may be separated by the 
handling of the device before the clip is left on the living tissue. 
Additionally, because silicone is used as the filler of the clip device as 
described above, the assembly of the device is not easy. Further, because 
silicone is expensive, the clip device is also expensive. On the other 
hand, Japanese Laid-Open Patent Application Publication No. Hei 5-212043 
describes that the gap between the grasping portions of the clip is 
reduced to ligate a polyp or a blood vessel. However, the grasping 
portions of the clip cannot reliably grasp the living tissue, because the 
tissue slips from the inner surfaces of the grasping portions. Further, if 
the end portions of the clip are shaped sharply, the tissue will be 
injured during the ligation. 
SUMMARY OF THE INVENTION 
An object of this invention is to provide a clip device which can simplify 
the handling of a clip before it is left on a living tissue, and can 
reliably grasp the tissue to be treated, and will not injure the tissue 
during the treatment. 
In order to attain the above object, a clip device for a living tissue in a 
body cavity according to this invention comprises an introducing tube 
insertable into the body cavity. An operating member of the clip device is 
advanceably and retreatably inserted into the introducing tube; the 
operating member has a distal end portion; An operating wire is 
advanceably and retreatably inserted into the operating member, and the 
operating wire has a distal end portion and a retainer attached to the 
distal end portion of the operating wire. The clip device further 
includes, a clip having a proximal end portion and a pair of arm portions 
extending from the proximal end portion and provided with a tendency to 
open. A clip squeezing ring is removably attached to the distal end 
portion of the operating member for closing the arm portions of the clip 
by fitting to the arm portions of the clip. A coupling member is 
insertable into the clip squeezing ring, and the coupling ring is 
removably engaged with the retainer. The coupling ring further includes a 
hook portion to be engaged with the proximal end portion of the clip. A 
holding member holds the coupling member inside the clip squeezing ring 
such that the coupling member can be removed from the clip squeezing ring 
when the operating wire is retreated. At least one of the arm portions is 
bent inward so as to be bow-shaped, and has an inner side provided with 
friction increasing structure for increasing friction between the inner 
side of the arm portion and the living tissue. 
Other characteristics and advantages of this invention will be apparent 
from the following description.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIGS. 1 to 8, a first embodiment of this invention will be 
described. A clip device of the first embodiment comprises a cassette-type 
clip unit 1 as shown in FIG. 1, and a clip operating device 6 as shown in 
FIG. 3. 
The clip unit 1 has a clip 2, a coupling plate 3 to be used as a coupling 
member, and a holding tube 4 to be used as a clip squeezing ring. 
The clip 2 is formed by a metallic plate, such as a leaf spring, which is 
bent at its center. Further, as shown in FIG. 1(B), the metallic plate 
intersects near the bent portion, and a pair of arm portions 2A and 2B 
having a tendency to open extend with their distal end portions separating 
from each other. On the proximal end side of the clip 2 a substantially 
oval-shaped proximal end portion 2d is formed. 
As shown in FIG. 1(A), the proximal end portion 2d of the clip 2 comprises 
a proximal curved portion 2g provided with a recess 2e. As shown in FIG. 
1(B), the curved portion 2g has a smaller radius of curvature than that of 
a curved portion 2h on the side of an intersecting portion 2c. The width 
WI of the oval portion of the proximal end portion 2d is larger than the 
inside diameter of the holding tube 4. 
Further, the arm portions 2A and 2B each are provided with a bow-shaped 
portion 2a which is bent inward so as to decrease the gap between the arm 
portions 2A and 2B when they are closed. The inner side of the bow-shaped 
portion 2a is provided with protrusions 2f. The number of the protrusions 
2f is preferably 4 to 8. The protrusions 2f of the arm portion 2A are 
positioned so as to abut on or be interposed between those of the arm 
portion 2B when the arm portions 2A and 2B are closed. Because the distal 
end portions of the arm portions 2A and 2B are folded back towards the 
proximal end side of the clip, the distal end portions of the clip 2 are 
obtuse. As shown in FIG. 1(C), when the arm portions 2A and 2B are closed, 
the whole bow-shaped portions 2a contact almost closely with each other 
owing to their elasticity. 
The coupling plate 3 is formed by photoetching or by pressing a metallic 
plate. As shown in FIG. 2(A), the coupling plate 3 is provided in its 
distal end portion with a hook portion 3A. The hook portion 3A is hooked 
on the recess 2e of the clip 2 to removably engage with the clip 2. The 
hook portion 3A comprises a straight portion 3a extending from a main body 
of the coupling plate 3 toward its distal end, an arc portion 3b extending 
from the strait portion 3a and forming a semicircle shape which turns to 
the proximal direction, and an inclined portion 3c further extending from 
the arc portion 3b towards the proximal direction. 
The width of the hook portion 3A from the straight portion 3a to the middle 
portion of the arc portion 3b is approximately the same. From the middle 
portion of the arc portion 3b to a boundary portion 3d between the arc 
portion 3b and the inclined portion 3c, the width gradually becomes 
narrow. That is, the width of the hook portion 3A is the narrowest at the 
boundary portion 3d. Further, the inclined portion 3c is formed so that it 
widens towards the outside of the hook portion 3A from the boundary 
portion 3d to an end portion 3e. Thus, as shown in FIG. 2(A), the width W2 
of the coupling plate 3 at the end portion 3e is the widest. 
As shown in FIG. 1(A), the proximal end side of the coupling plate 3 is 
provided with a large-diameter opening 3f and a small-diameter opening 3g 
connected with the large-diameter opening 3f. As shown in FIG. 4, the 
large-diameter opening 3f and the small-diameter opening 3g are engaged 
with a pin 15 provided to the distal end portion of the clip operating 
device 6 so that the coupling plate 3 is coupled to the clip operating 
device 6. 
As shown in FIG. 1(A), the holding tube 4 is substantially cylindrical and 
provided with a tapered portion 4a on the distal end side of its hollow 
portion. The outside shape of the holding tube 4 is formed by a 
large-diameter portion 4b on the distal end side of the holding tube 4, 
and a small-diameter portion 4c. As shown in FIG. 2(A), the maximum width 
W2 of the coupling plate 3 is larger than the inner diameter of the 
holding tube 4. However, the width W3 of the coupling plate 3 at the 
boundary portion 3d is smaller than the inner diameter of the holding tube 
4. 
The respective members are assembled in the following manner to construct 
the clip unit. The hook portion 3A of the coupling plate 3 is inserted 
through the substantially oval-shaped proximal end portion 2d of the clip 
2 and hooked on the recess 2e. In this state, the proximal end portion of 
the coupling plate 3 is inserted into the hollow of the holding tube 4 
from its distal end side. Because the coupling plate 3 is longer than the 
holding tube 4, the proximal end portion of the coupling plate 3 protrudes 
from the proximal end portion of the holding tube 4. 
The proximal end portion of the coupling plate 3 protruding from the 
holding tube 4 is held, and the coupling plate 3 is further pulled in the 
holding tube 4 until the clip 2 contacts the distal end portion of the 
holding tube 4, so that the hook portion 3A is elastically deformed by the 
tapered portion 4a of the holding tube 4 gradually. That is, the maximum 
width W2 of the coupling plate 3 at the end portion 3e of the hook portion 
3A is gradually reduced, and the end portion 3e generates an urging force 
that presses against the tapered portion 4a of the holding tube 4. The 
hook portion 3A is elastically deformed by being bent inward from the 
boundary portion 3d which has the narrowest width, that is, the smallest 
cross-sectional area of the hook portion 3A. 
After a while the end portion 3e passes the tapered portion 4a and reaches 
the inner wall of the holding tube 4 to press the inner wall. In this 
state, the coupling plate 3, which is provided with a sufficient resilient 
force due to the deformation of the hook portion 3A is temporarily held 
inside the holding tube 4, and the respective parts constructing the clip 
unit 1 are temporarily fixed and retained. The amount of the resilient 
force caused by the deformation of the hook portion 3A can be selected 
properly in accordance with the purpose, by selecting the material of the 
coupling plate 3 and the size and shape of the boundary portion 3d. 
The clip operating device 6 shown in FIG. 3 comprises a coil sheath 7 to be 
used as an operating member. The coil sheath 7 includes in the order from 
its distal end side a hollow coil pipe 7A and a hollow coil 7b fixed to 
the hollow coil pipe 7a. A tube sheath 8 is used as an introducing tube 
which covers the coil sheath 7. The coil sheath 7 and the tube sheath 8 
are assembled relatively movable to each other. An operating wire 13 
having a retainer 11 on its distal end side is advanceably and retreatably 
inserted through the coil sheath 7. A proximal end portion of the coil 
sheath 7 is coupled to a coil sheath operating portion 9, and a proximal 
end portion of the tube sheath 8 is coupled to a tube operating portion 10 
which is provided on an outside periphery of the coil sheath operating 
portion 9. The proximal end side of the operating wire 13 is coupled to a 
slider 12. 
The inside diameter of the coil pipe 7a is larger than the small-diameter 
portion 4c of the holding tube 4 so that the small-diameter portion 4c can 
be inserted in the coil pipe 7a, whereas the inside diameter of the coil 
pipe 7a is smaller than the large-diameter portion 4b so that the 
large-diameter portion 4b cannot be inserted in the coil pipe 7a. That is 
to say, a step portion between the small-diameter portion 4c and the 
large-diameter portion 4b abuts on the distal end of the coil pipe 7a. The 
outside diameter of the coil pipe 7a is approximately the same as the 
large-diameter portion 4b of the holding tube 4. 
The retainer 11 is rod-shaped and provided on its distal end side with a 
recess 14. The recess 14 is provided on its bottom with a pin 15 which is 
vertical to the advancing and retreating direction of the operating wire 
13. The pin 15 comprises a circular head portion 16 and a small-diameter 
portion 17 which has a smaller diameter than that of the head portion 16. 
The head portion 16 of the pin 15 is smaller than the large-diameter 
opening 3f of the coupling plate 3 as shown in FIG. 1(A) and is larger 
than the small-diameter opening 3g. Further, the small-diameter portion 17 
of the pin 15 is smaller than the small-diameter opening 3g of the 
coupling plate 3. 
The operation of the first embodiment will be described. When the clip unit 
1 is attached to the clip operating device 6 as shown in FIG. 4, the 
slider 12 is pushed toward the distal end side, crusing the retainer 11 to 
protrude from the coil pipe 7a. After the pin 15 of the retainer 11 is 
fitted in the large-diameter opening 3f of the coupling plate 3 of the 
clip unit 1, the entire clip unit 1 is pulled toward the distal end side. 
Then, the head portion 16 of the pin 15 is engaged with the small-diameter 
opening 3g of the coupling plate 3. Further, by pulling the slider 12 
toward the proximal end side, the retainer 11 is pulled in the coil sheath 
7 and the small-diameter potion 4c of the holding tube 4 is inserted into 
the coil pipe 7a to complete the attachment of the clip unit 1. 
Next, the tube sheath operating portion 10 is pushed toward the distal end 
side to cause the tube sheath 8 to protrude from the coil sheath 7 toward 
the distal end side so that the clip unit 1, which is already engaged with 
the retainer 11, is inserted into the tube sheath 8. With this operation, 
as shown in FIG. 5, the clip unit 1 is received in the hollow of the 
distal end portion of the tube sheath 8 with the arm portions 2A and 2B 
closed. In this state, the tube sheath 8 is introduced into a body cavity 
via a forceps channel of an endoscope that has been previously inserted 
into the body cavity. While the body cavity is observed via the endoscope, 
the distal end portion of the tube sheath 8 is guided to a part to be 
treated. 
Next, the tube sheath operating portion 10 is pulled toward the proximal 
end side to expose the clip unit 1 and the distal end portion of the coil 
sheath 7 from the tube sheath 8, as shown in FIG. 6. When the slider 12 is 
pulled toward the proximal end side to retreat the operating wire 13 
toward the proximal end side, the oval-shaped portion of the proximal end 
portion 2d of the clip 2 is squeezed, because the width W1 of the 
oval-shaped portion of the proximal end portion 2d of the clip 2 is larger 
than the inside diameter of the holding tube 4. Then, as shown in FIG. 6, 
the arm portions 2A and 2B largely open outward. 
In this state, the clip 2 is guided so that it will grasp the object 
tissue. By further pulling the slider 12 toward the proximal end side, the 
operating wire 13 is retracted, and the arm portions 2A and 2B of the clip 
2 are pulled in the holding tube 4. With this operation, the arm portions 
2A and 2B are closed as shown in FIG. 1(C). For example, as shown in FIG. 
1(D), when the arm portions 2A and 2B of the clip 2 grasp a stalk portion 
Q of a polyp P, the stalk portion can be grasped reliably by the entire 
bow-shaped portions 2a of the arm portions 2A and 2B owing to the 
elasticity of the bow-shaped portions 2a. 
When the arm portions 2A and 2B of the clip 2 reliably grasp the living 
tissue and the slider 12 is further pulled toward the proximal end side to 
retract the operating wire 13, the hook portion 3A of the coupling plate 3 
of the clip 2 is deformed and stretched as shown in FIGS. 7 and 8. The 
clip 2 disengages from the coupling plate 3, becomes detached from the 
clip operating device 6 and is left inside the body cavity, holding the 
tissue. Then, by using a conventional snare or the like, the end side of 
the tissue above the grasped portion is cut off and collected. Further, 
when ligating a varix such as an esophageal varix, the arm portions 2A and 
2B of the clip 2 clip the varix. Then the clip 2 is left in the body 
cavity for several weeks, and the varix will disappear. 
After disengaging the clip 2, the clip operating device 6is removed from 
the force ps channel of the endoscope. Then, the slider 12 is pushed 
towards the distal end side to protrude the retainer 11 from the coil 
sheath 7, and the coupling plate 3 with the hook portion 3A stretched as 
shown in FIG. 2(B) is removed from the retainer 11. At this time, because 
the hook portion 3A of the coupling plate 3 is stretched as stated above, 
of the end portion 3e of the coupling plate 3 no longer exerts pressure 
against the inner wall of the holding tube 4. Therefore, the coupling 
plate 3 is not caught on the inner wall of the coil 7b and can be removed 
easily. 
According to the first embodiment of this invention, because the end 
portion 3e of the hook portion 3A of the coupling plate 3 presses against 
the inner wall of the holding tube 4 to temporarily retain the respective 
members of the clip unit 1, the clip unit 1 can be assembled easily at a 
low cost. Further, the amount of the resilient force caused by the 
deformation of the hook portion 3A can be selected properly in accordance 
with the purpose, by selecting the material of the coupling plate 3 and 
the size and shape of the boundary portion 3d. Thus, the respective 
members of the clip unit 1 will not become separated by the handling of 
the clip device before the clip 2 is left on the living tissue. 
Furthermore, after the clip 2 is left on the living tissue since the hook 
portion 3A of the coupling plate 3 is stretched to completely extinguish 
the pressure against the inner wall of the holding tube, the coupling 
plate 3 can easily be removed from the coil 7b. Moreover, since the living 
tissue can be grasped by the entire bow-shaped portions 2a owing to the 
elasticity of the bow-shaped portions 2a of the arm portions 2A and 2B, 
and since the inner side of the arm portions 2A and 2B are provided with a 
plurality of protrusion 2f, the arm portions 2A and 2B can securely grasp 
and ligate the tissue without slipping. Further, because the distal end 
portions of the clip 2 are formed obtusely, the clip 2 will not injure the 
tissue and can be used safely. 
Next, referring to FIGS. 9(A) and 9(B), a second embodiment of this 
invention will be described. In this embodiment, the inner wall of a 
holding tube 4 is provided with a pair of protruding portions 4d which 
protrude inward. The shape of a coupling plate 3 is approximately the same 
as that of the first embodiment. However, the width of the outer side of 
the hook portion 3A is the same as the width of the coupling plate 3, and 
the hook portion 3A has the same cross-sectional area along its entire 
length, which is different from the first embodiment. The remaining 
structures of the second embodiment not discussed above are the same as 
that of the first embodiment. 
In the second embodiment, when the coupling plate 3 is inserted in the 
holding tube 4, it is pressed by the protruding portions 4d provided to 
the inner wall of the holding tube 4 and temporarily retained in the 
holding tube 4. 
When the living tissue is sandwiched by the arm portions 2A and 2B of the 
clip 2 and the slider 12 is pulled toward the proximal end side to retract 
the operating wire 13, the hook portion 3A of the coupling plate 3 of the 
clip 2 is deformed and stretched, and the clip 2 separates from the clip 
operating device 6 and is left inside the body cavity, grasping the living 
tissue. When the operating wire 13 is further retracted to the proximal 
end side, the coupling plate 3 is disengaged from the protruding portions 
4d provided in the holding tube 4 so that the pressure between the 
coupling plate 3 and the holding tube 4 disappears. 
According to the second embodiment, the shape of the coupling plate 3 can 
be simpler than that of the first embodiment. Further, the amount of the 
pressure between the coupling plate 3 and the inner wall of the holding 
tube 4 can be selected properly by selecting the height of the protruding 
portions 4d and the width of the coupling plate 3. Other functions and 
results are the same as those of the first embodiment. 
Referring to FIG. 10, a third embodiment of this invention will be 
described. This embodiment is different from the first embodiment in that 
the distal end portions of the arm portions 2A and 2B of the clip 2 are 
curled to be obtuse, and the inner sides of the arm portions 2A and 2B are 
provided with ridges resembling a file instead of protrusions. The 
functions and results of the third embodiment are the same as those of the 
first embodiment. Thus its description will be omitted. 
As described above, because the clip device of this invention is designed 
such that the coupling member can be held temporarily by the inner wall of 
the clip squeezing ring, the clip unit can be assembled easily at a low 
cost. Further, since the amount of the force for holding the squeezing 
ring and the coupling member can be selected properly by selecting the 
inside shape of the clip squeezing ring and the material and shape of the 
coupling member, the coupling member and the clip squeezing ring will not 
become separated by the handling of the clip device before the clip is 
left on the living tissue. Further, after the clip is left on the living 
tissue since the pressure between the coupling member and the inner wall 
of the squeezing ring has completely disappeared, the coupling member can 
be removed easily from the clip device. Furthermore, since the living 
tissue can be grasped by the entire bow-shaped portions owing to the 
elasticity of the bow-shaped portions provided to the clip, and since the 
inner sides of the arm portions of the clip are provided with a means for 
increasing the friction between the inner sides of the arm portions and 
the living tissue, the arm portions can reliably grasp and ligate the 
tissue without slipping. Moreover, because the distal end portions of the 
clip are formed obtusely, the clip will not injure the tissue and can be 
used safely. 
Further widely different embodiments of this invention may be made without 
departing from the spirit and scope of this invention. This invention will 
not be limited to the specific embodiments thereof except as defined in 
the appended claims.