Surgical anastomosis stapler

Improved medical suturing apparatus comprises a main body that consists of an operating member and an insertion member extending therefrom and an anvil head that is provided at the distal end of the main body for clinching a plurality of staples, said apparatus further including a staple head that has an array of staples and which is provided in a position opposed to the anvil head.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a medical suturing apparatus for use in 
surgical operations on tubular structures in the human body such as the 
intestine and esophagus. 
2. Related Art 
In the current practice of surgical operations on tubular structures such 
as intestine and esophagus, anastomosis is performed with a medical 
suturing apparatus comprising an operating member, an insertion member 
extending therefrom, a head disposed at the distal end of the insertion 
member which has a plurality of U-shaped staples arranged on the 
circumference, and an anvil disposed in a position opposed to the head for 
clinching the staples. 
Commonly known suturing apparatus are operated as follows: the head and the 
anvil are inserted into two opposed tubular structures and, after the 
distance between the head and the anvil is shortened, the staples are 
expelled and clinched by slots in the opposite surface of the anvil while, 
at the same time, the excess tissue left inside of the staple line is 
severed by a cylindrical blade positioned inside of the staple line, 
whereupon the intended anastomosis is completed. 
U.S. Pat. No. 5,392,979 discloses a suturing apparatus which permits the 
anvil to be attached to or detached from the head with comparative ease 
but in which the anvil is no longer detachable from the head if the 
distance between the two members has reached an optimal value for 
anastomosis. Then, a safety mechanism is released, whereupon it becomes 
possible to fire the staples. An indicator is used to provide a visual 
signal for the surgeon to know an optimal value of the head to anvil 
distance. A similar type of suturing apparatus is described in U.S. Pat. 
No. 5,205,459. 
The suturing apparatus described in the two U.S. patents are of a 
disposable type, which is different from the device proposed in Unexamined 
Published Japanese Patent Application (kokai) No. 108347/1980. The latter 
type consists of an operating member, an insertion member, a staple 
cartridge and an anvil. The operating member combines with the insertion 
member to comprise a main body and the staple cartridge and the anvil 
which are disposed at the distal end of the insertion member are replaced 
after each surgical operation whereas the main body is usable more than 
once. 
The suturing apparatus described above share the common structural feature 
that the legs of each staple disposed at the distal end of the insertion 
member are oriented distally so that they can be ejected in a distal 
direction. 
A problem with the suturing apparatus disclosed in U.S. Pat. Nos. 5,392,979 
and 5,205,459 is that even if the anvil is yet to be installed, the safety 
mechanism is released if the indicator signals an optimal distance for 
performing anastomosis and the surgeon may inadvertently fire staples, 
resulting in a waste of the staples or accidental ejecting of the circular 
blade. In addition, the suturing apparatus described in the two U.S. 
patents is of a disposable type and it must entirely be discarded after 
single use. Therefore, the apparatus must be purchased for each surgical 
operation and this only adds to the running cost of hospitals. 
In contrast, the suturing apparatus disclosed in Unexamined Published 
Japanese Patent Application No. 108347/1980 permits repeated use of the 
main body by replacing the anvil and the staple cartridge. However, the 
anvil of this apparatus is of such a construction that it is threadably 
mounted to the rod at the distal end of the insertion member and, 
therefore, it is not ideal for handling in surgical operations where 
simple and quick procedures of replacement are necessary. 
Further in addition, the known suturing apparatus for use in anastomotic 
surgical operations on tubular structures including the three devices 
described above share the common feature that the legs of staples are 
oriented distally and that therefore the surgeon cannot check immediately 
after his surgical operation as to whether the legs of the fired staples 
have been appropriately clinched; this has made it impossible to assure 
complete prevention of post-operative complications. 
SUMMARY OF THE INVENTION 
The present invention has been accomplished under these circumstances and 
has as an object providing a medical suturing apparatus that prevents 
unnecessary firing of staples, that permits simple replacements of the 
staple cartridge and the anvil head, that does not add to the running cost 
of medical institutions and that reduces the chance of the occurrence of 
post-operative complications. 
Another object of the invention is to provide a medical suturing apparatus 
which, after the anvil has been installed at the distal end of the 
insertion member, prevents the anvil from being disconnected as the 
distance between the anvil and the head at the distal end of the insertion 
member is being adjusted and which also ensures that even if the lever of 
the operating member is gripped after staples have been fired, no troubles 
such as damage due to the inadvertent ejecting of the cylindrical cutter 
will occur. 
The first object of the invention can be attained by a medical suturing 
apparatus including a main body that consists of an operating member and 
an insertion member extending therefrom and an anvil head that is disposed 
at the distal end of said main body for clinching a plurality of staples, 
characterized in that a staple head having an array of staples is disposed 
in a position opposed to the anvil head. 
The suturing apparatus is used as follows in an anastomotic surgical 
operation. The staple head is inserted into an end of a severed section of 
the intestine and with a thin elongated linking portion of the staple head 
sticking out of the section, said one end of the intestine is purse-string 
sutured. The insertion member of the apparatus is inserted into either 
another incised area of the intestine or an opening of the patient and the 
other end of the severed section is purse-string sutured with the linking 
portion of the staple head at the distal end of the insertion member 
sticking out of said other end of the intestine. 
After both ends of the intestine have been purse-string sutured, the staple 
head is installed on the linking portion at the distal end of the 
insertion member and the adjusting knob of the operating member is rotated 
to advance the staple head toward the anvil head. When the distance 
between the staple and the anvil head has reached an appropriate value for 
anastomosis, the lever of the operating member is gripped, whereupon the 
necessary force is transmitted through the linking portion of the staple 
head which connects to the distal end of the insertion member and staples 
are expelled from the staple head and their legs are clinched by means of 
the slots in the anvil head. At the same time, the excess tissue inside of 
the staple line is severed off with a cylindrical cutter. 
The second object of the invention can be attained by a medical suturing 
apparatus including an operating member, an insertion member extending 
from said operating member, and an anvil head disposed at the head of said 
insertion member for clinching a plurality of staples, characterized in 
that said anvil head is detachable with respect to the head of the 
insertion member and that when said anvil head is installed on the head of 
the insertion member, the distance between said anvil head and said head 
of the insertion member can be fixed at desired value. 
The suturing apparatus is used as follows in an anastomotic surgical 
operation. The anvil head is inserted into an end of a severed section of 
the intestine and said one end of the intestine is purse-string sutured 
around an anvil shaft from the anvil head which sticks out of the section. 
The insertion member of the apparatus is inserted into either another 
incised area of the intestine or an anal opening of the patient and the 
other end of the severed section is purse-string sutured with a trocar at 
the distal end of the insertion member sticking out of said other end of 
the section. 
After both ends of the intestine have been purse-string sutured, the anvil 
shaft is installed on the head of the insertion member, with the trocar 
used as a guide, and the locking mechanism of the operating member is 
manipulated to ensure that the anvil head cannot be disconnected from the 
trocar. Thereafter, the adjusting knob of the operating member is rotated 
to move the anvil head toward the head of the insertion member. Having 
been already locked, the anvil head will not inadvertently be disconnected 
as it is moved toward the head of the insertion member. 
When the distance between the anvil head and the head of the head of the 
insertion member has reached an optimal value for anastomosis, the safety 
lock is released and the lever of the operating member is gripped, 
whereupon staples are expelled toward the anvil head and clinched; at the 
same time, a cylindrical cutter severs off the excess tissue inside of the 
staple line to thereby complete the anastomotic operation. If desired, the 
anvil head can be disconnected from the head of the insertion member at 
any position in the process of moving the former toward the latter.

DETAILED DESCRIPTION OF THE INVENTION 
Various embodiments of the present invention will now be described with 
reference to the accompanying drawings. 
FIGS. 1 to 12 illustrate a first embodiment. As shown in FIG. 1A, a medical 
suturing apparatus generally indicated by 1 comprises a main body 2 which 
is composed of an operating member 3 and an insertion member 4 extending 
with a mild curvature from the operating member 3. Provided at the distal 
end of the insertion member 4 is an anvil head 5 which is to be described 
below more specifically. A staple head 6 which will also be described 
below more specifically is detachably provided on the anvil head 5. 
The operating member 3 is fitted with an adjusting knob 7 which is rotated 
to retract the staple head 6 toward the anvil head 5, and a lever 8 which 
is gripped to have staples 11 (see below) expelled as a tissue binding 
fastener from the staple head 6. 
The staple head 6 and the distal end of the insertion member 4 have the 
structural features which are described below with reference to FIGS. 2 to 
5. As shown in FIG. 2D, each staple 11 is U-shaped and consists of a base 
11a and two legs 11b which are generally perpendicular to the base 11a. 
As shown in FIGS. 2A and 2B, the staple head 6 is fitted in a position 
opposed to the anvil head 5 which is provided at the distal end of the 
insertion member 4 and the staple head 6 normally contains a plurality of 
staples 11 in an annular array of recessed staple channels 12. The staples 
11 in the staple channels are oriented in such a way that the tips of the 
two legs 11b extending from the bases 11a are directed toward the anvil 
head 5. Provided inward of the staple channels 12 is a cylindrical cutter 
13 that is coaxial with the channels and which will cut off a tissue 
section. The cutter 13 has a sharp blade 13a directed toward the anvil 
head 5 and it is fitted on a staple pusher 14 which expels staples 11 by 
directly pushing them out. 
The anvil head side of the staple pusher 14 is provided with a plurality of 
rod-shaped projections 14a which are partially inserted into the 
respective staple channels 12. A staple drive shaft 15 for driving the 
staple pusher 14 is fixed through axial the center of the staple pusher 
14. 
The anvil head side of the staple drive shaft 15 is fitted with a pair of 
leaf springs 16 and the distal end of each leaf spring which is on the 
anvil head side is provided with an inwardly projecting latch 17. The 
anvil head side of the staple head 6 is provided with a staple head sleeve 
18 for accommodating the staple drive shaft 15 and the leaf springs 16. 
As shown in FIGS. 3 and 4, a pair of leaf springs 19 are molded on the 
anvil head side of the staple head sleeve 18. The distal end of each leaf 
spring 19 is provided with an inwardly projecting latch 20. Leaf spring 
guiding slots 18a are provided on the outer circumference of the staple 
head sleeve 18 for permitting the heads of leaf springs 16a to become 
flared to come outside of the outer circumference of the staple head 
sleeve 18. The leaf spring guiding slots 18a are sized to be longer than 
the axial length of the leaf spring heads 16a. As shown in FIGS. 1B and 
FIG. 4A, a plurality of ribs 21 are provided on the outer circumference of 
the anvil head side of the staple head sleeve 18 as means of positioning 
it in the radial direction of staples 11. 
Further, as shown in FIG. 2B, a staple channel casing 12a forming the 
staple channels 12 has a keyway 22 which is positioned by a rib 23 formed 
distally on the staple head sleeve 18. This allows the positioning of the 
staple head sleeve 18 with respect to the radial direction of staples 11. 
The individual parts to be accommodated within the staple head 6 are 
retained by a staple head casing 24. 
As shown in FIG. 2C, the anvil head 5 at the distal end of the insertion 
member 4 is provided with an anvil 26 which has an annular array of slots 
25 for clinching staples 11. Means 27 is also provided to position the 
slots 25 in a radial direction. A plate 28 for receiving the cylindrical 
cutter 13 is provided coaxially with the anvil 26 and in a position 
opposed to the cutter 13, and a trocar 30 is provided inward of and 
through the center of the receiving plate 28. 
The trocar 30 is provided with circular grooves 29 which engage the latches 
17 at the distal end of the leaf springs 16 fitted on the staple drive 
shaft 15. The trocar 30 is coupled to a trocar drive guide 31 on the 
actuator side and a trocar drive member 32 is provided to ensure that the 
force produced by gripping the lever 8 of the actuator 3 is transmitted to 
the trocar drive guide 31. Provided exterior to the trocar 30 is a trocar 
sleeve 34 that accommodates the trocar 30 and which has circular grooves 
33 that engage the latches 20 at the distal end of the leaf springs 19 
fitted on the staple head sleeve 18. 
As shown in FIG. 3, the trocar sleeve 34 is coupled on the actuator side to 
a staple head drive guide 35 and a tension member 36 is also provided for 
ensuring that the force produced by rotating the adjusting knob 7 of the 
actuator 3 is transmitted to the staple head drive guide 35. The trocar 
drive guide 31 and the staple head drive guide 35 perform such a function 
within the insertion member 4 that a positional relationship in which the 
trocar drive member 32 is not coaxial with the tension member 36 is 
transformed to a relationship in which the trocar 30 is coaxial with the 
trocar sleeve 34. The trocar sleeve 34 is accommodated in the anvil head 
5, which is internally provided with a plurality of keyways 37 for 
positioning the staple head 6 in a radial direction. 
Having described above the construction of the medical suturing apparatus 
according to the first embodiment of the invention, we now describe how it 
is operated. 
First, the staple head 6 is inserted into an end of a tissue section of a 
tubular structure, say, intestine and said one end is purse-string sutured 
around the staple head sleeve 18. In addition, the insertion member 4 is 
inserted into the other end of the tissue section and said other end is 
also purse-string sutured around the trocar sleeve 34. 
Thereafter, the trocar 30 and the trocar sleeve 34 are inserted into the 
staple head sleeve 18 of the staple head 6, whereupon the heads of leaf 
springs 16a will flare to come outside of the leaf spring guiding slots 
18a, causing the staple head 6 to be installed at the distal end of the 
insertion member 4. In this case, the circular grooves 29 at the distal 
end of the trocar 30 and the circular grooves 33 on the trocar sleeve 34 
are in engagement with the latches 17 and 20, respectively (see FIG. 2A). 
When the adjusting knob 7 of the operating member 3 is rotated, a tension 
is transmitted through the staple head drive member 36, staple head drive 
guide 35 and trocar sleeve 34 to reach the staple head sleeve 18, causing 
the staple head 6 to be retracted toward the anvil head 5 (see FIG. 5A). 
When the staple head 6 has been retracted to a certain extent, the ribs 21 
on the staple head sleeve 18 come into engagement with the keyways 37 on 
the inner surface of the anvil head 5, whereby the radial positioning of 
the staple head 6 is completed automatically. FIG. 5B shows how the ribs 
21 engage the keyways 37 on the anvil head 5 and how the leaf spring heads 
16a contact ridges 37a between adjacent keyways 37. 
If the indicator (not shown) signals the surgeon that the distance between 
anvil 26 and staple head 6 has attained an optimal value for performing 
anastomosis, the surgeon releases the safety lock (not shown). If he grips 
the lever 8, the tension is transmitted through the trocar drive member 
32, trocar drive guide 31, trocar 30, leaf springs 16 and staple drive 
shaft 15 to reach the staple pusher 14, which then causes staples 11 to be 
ejected from the staple channels 12 as shown in FIG. 6A. The ejected 
staples 11 are clinched by the slots 25 in the anvil 26. FIG. 6B shows a 
clinched staple 11. Under the tension transmitted from the operating 
member 3, the leaf spring heads 16a tend to flare outwardly but, in fact, 
the ridges 37a between adjacent keyways 37 prevent those heads from 
flaring but, instead, they will be moved toward the actuator 3 along the 
leaf spring guiding slots 18a, thereby restricting the action of the 
staple pusher 14 such that it will not move toward the operating member 3 
by a more-than-necessary amount (see FIG. 4B). At the same time, the 
cylindrical cutter 13 is pushed out of the staple head 6 to sever the 
excess tissue of the intestine inside of the staple line, whereby the 
anastomotic operation is completed. 
We next describe the proximal side of the operating member 3 and the 
insertion member 4 by referring to FIGS. 7 to 12. As shown in FIG. 7 which 
is an exploded view of the insertion member 4, the interior of the 
proximal side of the insertion member 4 comprises the staple head drive 
member 36 and the trocar drive member 32 which are contained in a curved 
insertion shaft 46, with the member 32 being held between guide members 
45a and 45b and the member 36 held between guide members 45b and 45c, such 
that the member 32 is axially movable between the guide members 45a and 
45b whereas the member 36 is axially movable between the guide members 45b 
and 45c, with the radial relative positions of the two members 32 and 36 
being invariable throughout the insertion shaft 46. The trocar drive 
member 32 is pierced at the proximal end to make a hole 32a. 
As shown in FIG. 8, the operating member 3 contains a rod 47 which extends 
through the axial center to fit in semicircular grooves 49 provided in two 
casings 48a and 48b which compose the operating member 3. The proximal 
side of the rod 47 has a portion provided with an angular external thread 
50 and this portion is threaded into an angular screw shaft 51 provided 
with an angular internal thread 52. The rotatable adjusting knob 7 is 
provided at the proximal end of the angular screw shaft 51. 
A sheet-like safety guide 53 is mounted to the rod 47. The safety guide 53 
engages a rectangular groove 54 provided near the distal end of the casing 
48a. The trocar drive member 32 is mounted at the distal end of the rod 47 
in such a way that it is slidable relation to the rod 47. The staple head 
drive member 36 is also mounted to the rod 47. The insertion shaft 46 is 
mounted in such a way that it is held between two casings 48a and 48b. 
A U-shaped staple actuating member 55 is slidably disposed within the 
casing 48 such that it surrounds the rod 47. A latch 57 is fixed to the 
top surface of the staple actuating member 55. Arms 58a and 58b are 
mounted to opposite lateral sides of the staple actuating member 55 by 
means of pins 56. The arms 58a and 58b are rotatably mounted to triggers 
59a and 59b, respectively. Triggers 59a and 59b are mounted such that they 
are free to rotate-about a thick pin 60 mounted to the casing 48. A coil 
spring 61 is passed through the thick pin 60 and an end of it is fixed to 
the trigger 59a. The triggers 59a and 59b are fixed in such a way that a 
lever 62 is held therebetween. 
Underneath the safety guide 53 is provided a safety lock 63 which is 
mounted to the casings 48a and 48b in an axially rotatable manner such 
that its top surface 63a will contact the underside of the safety guide 
53, with the locking portion 63b being in contact with the edge 59c at the 
proximal end of the trigger 59a. An indicator 64 is rotatably mounted to 
the inner lateral side of the casing 48b in such a way that it is distally 
urged by means of a J-shaped leaf springs 65. A release lever 66 has a pin 
67 at an end and a tension spring 68 at the other end. The release lever 
66 is rotatably mounted to the casing 48b, with a finger grip 66a sticking 
out of it through a slot 69 made in it. The slot 69 is of such a shape as 
to enable the actuating of the finger grip 66a. 
We now describe the operation of the suturing apparatus according to the 
first embodiment of the invention. First consider the initial state shown 
in FIG. 9. When the adjusting knob 7 of the operating member 3 is rotated 
clockwise, the rod 47 is actuated by the angular thread to be retracted 
toward the adjusting knob 7 (or the operator), whereupon a tension is 
exerted on the staple head drive member 36 fitted to the distal end of the 
rod 47 and transmitted through the staple head drive guide 35 to reach the 
trocar sleeve 34 such that the staple head 6 installed on the trocar 
sleeve 34 is moved to a retracted position. 
In this process, a moment is exerted on the rod 47; however, the rod will 
not rotate since the safety guide 53 is slidably mounted to the 
rectangular groove 54 which serves to prevent the rotation of the rod 47. 
In addition, even at a time just before the staple head 6 is fully 
retracted toward the operator, the safety guide 53 will get into the 
U-shaped staple actuating member 55 to thereby prevent the rod 47 from 
rotating. 
When the indicator 64 gives the surgeon a visual signal indicating that the 
distance between the staple head 6 and the anvil 26 has reached an optimal 
value, the safety guide 53 in the casing 48 is disengaged from the top 
surface 63a of the safety lock 63. In addition, the trocar drive member 32 
slidably fitted to the distal end of the rod 47 is also retracted to the 
operator, causing the latch 57 to come into engagement with the hole 32a 
made at the proximal end of the trocar drive member 32 (see FIG. 10). 
Then, the safety lock 63 is rotated about an axis parallel to the axis of 
the rod 47, whereupon the locking portion 63b which has been in contact 
with the edge 59c at the proximal end of the trigger 59a is disengaged 
from it, causing the triggers 59a and 59b to become freely rotatable. If 
the surgeon grips the lever 62, the triggers 59a and 59b will rotate about 
the thick pin 60, so that the arms 58a and 58b which are rotatably fitted 
to the triggers 59a and 59b, respectively, are pushed toward the proximal 
end, thereby causing the staple actuating member 55 to be retracted toward 
the proximal end via elongated pins 56. 
In this process, a tension is also exerted on the trocar drive member 32 
which is in engagement with the latch 57 on top of the staple actuating 
member 55, causing the trocar 30 at the distal end of the insertion member 
4 to be moved to the retracted position via the trocar drive guide 31; as 
a result, staples 11 are fired from within the staple head 6 (see FIG. 11) 
. 
After the firing of the staples 11, the lever 62 is released, whereupon the 
triggers 59a and 59b return to their initial position by the action of the 
coil spring 61 and a compressive force is transmitted through arms 
59a/58b, staple actuating member 55, latch 57 and trocar drive member 32 
to reach the trocar 30 such that the rod-shaped projections 14a of the 
staple pusher 14 are eventually retracted into the staple channels 12. In 
this case, the leaf springs 19 in the staple head sleeve 18 are in contact 
with the inner surface of the anvil head 5 so they will not flare but 
prevent the staple head 6 from being disconnected from the anvil head 5. 
After the firing of the staples 11, the distance between the staple head 6 
and the anvil head 26 is increased by lowering release lever 66 on the 
casing 48b of the operating member as shown in FIG. 12. The pin 67 on the 
release lever 66 will then contact the trocar drive member 32 to raise it, 
whereupon the hole 32a in the trocar drive member 32 comes out of 
engagement with the latch 57 on the staple actuating member 55. If the 
adjusting knob 7 is rotated counterclockwise, a compressive force is 
exerted on the staple head drive member 36 and the trocar sleeve 34 is 
pushed distally via the staple head drive guide 35, whereupon the staple 
head 6 is moved distally away from the anvil head 5. 
After the hole 32a in the trocar drive member 32 has come out of engagement 
with the latch 57 to eventually cause the distal movement of the staple 
head 6, the surgeon may remove the finger from the finger grip 66a of the 
release lever 66 so as to bring it into the initial position. 
In order to withdraw the medical suturing apparatus 1 from a tubular 
structure such as a section of the intestine, the release lever 66 of the 
operating member 3 may be lowered, whereupon the trocar drive member 32 is 
disengaged from the latch 57; if the adjusting knob 7 is then rotated 
counterclockwise (by about 120 degrees), the staple head 6 will depart 
from the anvil head 5. If the lever 8 is gripped with force in this 
condition, neither the rod-shaped projections 14a of the staple pusher 14 
nor the cylindrical cutter 13 will project beyond the staple head 6. 
Subsequently, the insertion member 4 is rotated to be withdrawn from the 
section of the intestine. The staple head 6 of the used medical suturing 
apparatus 1 is removed from the trocar sleeve 34 and a new staple head 6 
is replaced to enable repeated use of the main body 2. 
Thus, the staple head 6 is incapable of firing staples 11 or ejecting the 
cylindrical cutter 13 on its own. Staples can only be fired after the 
passage of the following three stages: installing the staple head 6 at the 
distal end of the insertion member 4; adjusting the distance between the 
staple head 6 and the anvil head 5; and releasing the safety lock 63. 
Compared to the conventional medical suturing apparatus, the apparatus of 
the invention has the advantage that even if assistants to the surgeon 
forget to equip the suturing apparatus with the anvil head, unnecessary 
firing of staples can be precluded and the adverse effect of the 
cylindrical cutter can be prevented to thereby ensure utmost safety until 
an anastomotic operation is completed. 
The conventional suturing apparatus have had another problem in that once 
the safety lock has been released, the gripping of the lever of the used 
apparatus will cause the staple pusher or the cylindrical cutter to be 
ejected no matter where the anvil head is positioned. This is not the case 
with the medical suturing apparatus of the first embodiment of the 
invention; even if the surgeon inadvertently grips the lever 62 with the 
safety lock 63 having been released after the firing of staples in the 
surgical operation, neither the rod-shaped projections 14a of the staple 
pusher 14 nor the cylindrical cutter 13 will be ejected from the staple 
head 6 unless the distance between the anvil surface 26 and the staple 
head 6 has reached an appropriate value for firing staples 11; this offers 
the advantage of securing great safety after the anastomotic operation. 
Another advantage of the suturing apparatus of the invention is that the 
staple 11 in the staple head 6 have the legs 11b oriented toward the anal 
opening of the patient (i.e., toward the operator); therefore, after a 
sequence of steps in the anastomotic operation, the surgeon may insert an 
endoscope into the anal opening of the patient in order to check if the 
legs 11b of the fired staples 11 have been properly clinched. Thus, the 
occurrence of post-operative complications can be minimized. 
Yet another advantage of the suturing apparatus of the invention is that it 
permits repeated use of the main body 2 since the spent staple head 6 can 
be disconnected form the distal end of the insertion member 4 and a new 
staple head 6 may simply be replaced. Hence, compared to the disposable 
type, the suturing apparatus of the invention which can be used many times 
will not add to the running cost of medical institutions. Further in 
addition, the cylindrical cutter 13 which is accommodated within the 
staple head 6 can be replaced with a new cutter concurrently with the 
replacement of the staple head; therefore, high cutting performance will 
be maintained for an indefinite period. 
FIG. 13 shows a second embodiment of the invention and the structural parts 
which are identical to those employed in the first embodiment are 
identified by like numerals and will not be described in detail. The 
second embodiment is essentially the same as the first embodiment except 
for the following: the staple head sleeve 18 is replaced by a staple head 
sleeve 18a; the staple drive shaft 15 is replaced by a staple head shaft 
38; the trocar 30 is coupled to the staple head drive member 36; and the 
trocar sleeve 34 is coupled to the trocar drive member 32. 
The staple head sleeve 18a in the second embodiment is fitted to the staple 
pusher 14 and the staple head shaft 38 supports the staple head 6. The 
trocar 30 at the distal end of the insertion member 4 is connected to the 
adjusting knob 7 of the operating member 3 via the staple head drive 
member 36 in the insertion shaft 46 and the trocar sleeve 34 is so adapted 
that the force produced by gripping the lever 8 is transmitted through the 
trocar drive member 32 in the insertion shaft 46. 
The staple head sleeve 18a is designed to be mountable to the trocar sleeve 
34 at the distal end of the insertion member 4 and the leaf springs 16 
fitted on the staple head shaft 38 are designed to be mountable on the 
trocar 30 by means of latches 17. 
Having these structural features, the medical suturing apparatus of the 
second embodiment is used as follows. To begin with, as in the first 
embodiment, two ends of a section of the intestine are purse-string 
sutured around the staple head sleeve 18a and the trocar sleeve 34. If the 
staple head 6 is installed on the trocar 30 at the distal end of the 
insertion member 4, the staple head sleeve 18a is mounted on the trocar 
sleeve 34 whereas the leaf springs 16 fitted in the staple head shaft 38 
are mounted to the trocar 30. 
When the adjusting knob 7 of the operating member 3 is rotated, a tension 
is transmitted to the trocar 30 through the staple head drive member 36; 
the tension is further transmitted through the leaf springs 16 and staple 
head shaft 38 to reach the staple head 6, whereupon said staple head 6 is 
moved toward the anvil head 5. 
When the relative positions of the staple head 6 and the anvil 26 have 
attained an optimal relationship, the surgeon grips the lever 8 of the 
operating member 3, whereupon the tension is transmitted through the 
trocar drive member 32, trocar sleeve 34 and the staple head sleeve 18a to 
reach the staple pusher 14, which then causes staples 11 to be ejected 
from the staple channels 12. The ejected staples 11 are clinched by the 
slots 25 in the anvil 26. At the same time, the cylindrical cutter 13 is 
pushed out of the staple head 6 to sever the excess tissue of the 
intestine inside the staple line, whereby the anastomotic operation is 
completed. 
Thus, the second embodiment produces the same result as the first 
embodiment. 
FIG. 14 shows a third embodiment of the invention and the structural parts 
which are identical to those employed in the first embodiment are 
identified by like numerals and will not be described in detail. The third 
embodiment is essentially the same as the first embodiment except for the 
following: the staple head assembly 6 consists of two staple heads 6a and 
6b having different outside diameters; the anvil head assembly 5 of the 
main body 2 is so adapted that two anvils 26a and 26b of different outside 
diameters and two receiving plates 28a and 28b of different outside 
diameters can selectively be mounted to and dismounted from the anvil head 
assembly 5. It should be noted that the anvils 26a and 26b are mounted to 
the receiving plates 28a and 28b, respectively, so that they can be 
mounted to and dismounted from the anvil head assembly as a single anvil 
set 39a or 39b. In order to prevent wrong combinations, the staple head 6a 
and anvil set 39a which have a first outside diameter combination are 
desirably baled together, and so are the staple head 6b and anvil set 39b 
which have a second outside diameter combination. 
The third embodiment offers the following advantage: even if the outside 
diameter of a first selected staple head 6a does not fit the inside 
diameter of a section of the intestine to which anastomosis is to be 
applied, the main body 2 need not be simply discarded but it may still be 
used after replacing the staple head 6a with a second staple head 6b of a 
different outside diameter which accommodates staples 11. At the same 
time, the anvil set 39b consisting of the anvil 26b which is mounted to 
the receiving plate 28b and baled together with it may be placed in 
registry using the positioning means 27 such that the anvil set 39b can be 
replaced on the anvil head 5 of the main body 2. 
According to the third embodiment of the invention, the advantages of the 
first embodiment are of course attained. In addition, it provides a 
particular advantage over the disposable type of anastomotic suturing 
device which has to be totally discarded even if one finds that the staple 
head or anvil head in an unpacked bale does not have an outside diameter 
that fits the inside diameter of a section of a tubular structure such as 
the intestine; the advantage of the suturing apparatus according to the 
third embodiment is such that even in this situation, the main body 2 can 
still be used by replacing the staple head 6a with staple head 6b of a 
different size or vice versa. Further in addition, the main body 2 can 
repeatedly be used by replacing the spent staple head 6a with a new staple 
head 6b or vice versa. Because of these advantages, a substantial cost 
reduction can be realized in hospitals as compared to the use of 
disposable suturing apparatus. 
FIG. 15 shows a fourth embodiment of the invention and the structural parts 
which are identical to those employed in the first and second embodiments 
are identified by like numerals and will not be described in detail. The 
fourth embodiment is essentially the same as the first and second 
embodiments except for the following: the cylindrical cutter 13 is 
replaced by a cylindrical cutter 40 which is placed within the anvil head 
5, with its sharp blade 40a directed toward the staple head 6; the 
cylindrical cutter 40 is actuated by drive means which consists of racks 
41 on the outer circumference of the staple head sleeve 18a, racks 43 on 
the inner side of the cylindrical cutter 40, and pinions 42 meshing with 
the racks 41 and 43; and receiving plates 44 are disposed within the 
staple head 6 which is in a face-to-face relationship with the cylindrical 
cutter 40. 
Having these structural features, the medical suturing apparatus of the 
fourth embodiment is used as follows. To begin with, as in the first and 
second embodiments, two ends of a section of the intestine are 
purse-string sutured around the staple head sleeve 18a and the trocar 
sleeve 34. If the staple head 6 is fitted to the trocar 30 at the distal 
end of the insertion member 4, the staple head sleeve 18a is mounted to 
the trocar sleeve 34 whereas the leaf springs 16 fitted in the staple head 
shaft 38 are mounted to the trocar 30. When the adjusting knob 7 of the 
operating member 3 is rotated, a tension transmitted to the trocar 30 is 
further transmitted to the leaf springs 16 and the staple head 6, which is 
then moved toward the anvil 26 (see FIG. 15A). 
When the relative positions of the staple head 6 and the anvil 26 have 
attained an optional relationship, the surgeon grips the lever 8 of the 
operating member 3, whereupon the tensions transmitted through the trocar 
sleeve 34 and the staple head sleeve 18a to reach the staple pusher 14, 
which then causes staple 11 to be ejected from the staple channels 12. 
The ejected staples 11 are clinched by the slots 25 in the anvil 26. At the 
same time, the staple head sleeve 18a is retracted toward the anvil head 
5, whereupon the racks 41 move the racks 43 toward the staple head 6 via 
pinions 42, causing the sharp blade 40a of the cylindrical cutter 40 to 
project from the anvil head 5. 
Then, the cylindrical cutter 40 is urged against the receiving plate 44 in 
the staple head 6 to sever the excess tissue of the intestine inside the 
staple line, whereby the anastomotic operation is completed (see FIG. 
15B). After the end of the surgical operation, the staple head 6 is 
discarded and the main body 2 is fitted with a new staple head 6 for 
subsequent use. 
According to the fourth embodiment, the advantages of the second embodiment 
are attained and, in addition, the disposing of the cylindrical cutter 40 
within the anvil head of the main body 2 contributes to reduce the cost of 
replacement of staple head 6 and this results in a saving of the cost of 
each surgical operation. 
FIG. 16 shows a fifth embodiment of the invention and the structural parts 
which are identical to those employed in the third embodiment are 
identified by like numerals and will not be described in detail. The third 
embodiment is essentially the same as the third embodiment except for the 
following: staple head 6a and anvil set 39a are packed together in a bale 
70a of a first size whereas staple head 6b and anvil set 39b are packed 
together in a bale 70b of a second size; the staple head 6a and anvil set 
39a are each fitted with a size color 71a whereas the staple head 6b and 
anvil set 39b are each fitted with a different size color 71b. 
The fifth embodiment offers the following advantage: if the staple head 6a 
and the anvil set 39a which are taken out of the bale 70 (see FIG. 16A) do 
not fit the inside diameter of the intestine to which anastomos is to be 
applied, the surgeon may unpack the bale 70b of a different size and use 
the staple head 6b and anvil set 39b which will fit the inside diameter of 
the tissue section. If the right combination of sizes is not known, the 
surgeon may refer to the size colors 71a and 71b which are provided for 
the respective combinations of staple head (6a or 6b) and anvil set (39a 
or 39b). 
In addition to the advantages of the third embodiment, the fifth embodiment 
offers the following advantages: the staple head 6a and anvil head set 39a 
are packed together in the bale 70a of a first size whereas the staple 
head 6b and anvil set 39b are packed together in the bale 70b of a second 
size and, therefore, only one of the bales need be unpacked. Even if both 
bales are unpacked, the right combination of staple head and anvil set can 
be identified by referring to different size colors 71a and 71b. This 
eliminates inadvertent combining of a staple head of a first size with an 
anvil set of a second size and vice versa. The same results are achieved 
even if the size colors are replaced by similar devices such as other size 
indices and combination elements. 
FIGS. 17 to 24 illustrate a medical suturing apparatus according to a sixth 
embodiment of the invention. FIG. 17A shows a general overall view of the 
medical suturing apparatus which is generally indicated by 101. The main 
body 102 of the apparatus is composed of an operating member 103 and an 
insertion member 104 extending distally from the operating member 103. The 
distal end of the insertion member 104 is fitted with a detachable anvil 
head 105. The operating member 103 comprises a rotatable adjusting knob 
106, a lever 107 and a slider switch 108. A detailed construction of the 
operating member 103 will be described below. 
FIG. 17B shows the construction of the distal end of the insertion member 
104 which has the anvil head 105 installed on the head 109. The anvil head 
105 is shown in FIG. 18A, the head of the insertion member 109 in FIG. 
18B, and a cross section of the head 109 in FIG. 18C. 
As is clear from FIGS. 18A to 18C, the distal end of the insertion member 
104 is provided with a trocar 114 disposed in the center to serve as a 
guide for installing an anvil shaft 112 (to be described later) at the 
distal end of the insertion member 104, a tubular trocar sleeve 115 which 
covers the trocar 114, and outwardly flared leaf springs 116 formed by 
axially slotting the outer circumference of the trocar sleeve 115. 
The trocar sleeve 115 and the leaf springs 116 are fixed at the basal end 
to the trocar 114. Inwardly projecting latches 117 are provided at the 
distal end of the leaf springs 116. The trocar sleeve 115 is surrounded by 
a tubular outer sleeve 118 which is capable of moving back and forth 
relative to the trocar 114. 
As shown in FIG. 18B, the head of the insertion member 109 has an annular 
array of staple channels 120 each accommodating a staple 119. As shown in 
FIG. 18C, the head of the insertion member 109 has a staple pusher 123 
having a plurality of rod-shaped projections 123a for direct expelling of 
staples 119. The rod-shaped projections 123a are inserted into the 
respective staple channels 120 in a ring pattern. The staple channels 120 
are formed of a staple channel casing 122, which is internally provided 
with a cylindrical cutter 121 that is fixed to the staple pusher 123. 
As shown in FIG. 19A, a rod 124 is disposed through the center of the 
operating member 103 and a rod screw 124a disposed at the proximal end of 
the rod 124 is threaded into a rotating screw 125 in the adjusting knob 
106 (see FIG. 17). The rod 124 is partly provided with a safety guide 127 
and a rod groove 124b whereas a trocar drive member 128 is fixed at the 
distal end of the rod 124; a distal edge 127a is provided at the distal 
end of the safety guide 127. 
The safety guide 127 is in contact with the top surface 130a of a safety 
lock 130 and the safety lock 130 is mounted to a casing 131 in such a way 
that it is rotatable about an axis parallel to the rod 124. An outer 
sleeve drive member 132 is disposed above and close to the rod 124 and a 
slider switch 108 is disposed at the proximal end of the outer sleeve 
drive member 132 in such a way that it is capable of moving back and forth 
relative to the casing 131. Provided below the slider switch 108 is a 
slider latch 108a which is free to come into or out of engagement with the 
rod groove 124b. 
A trigger 133 is fixed to the lever 107 and this is mounted to the casing 
131 in such a way that it is free to rotate about a pin 134. A coil spring 
135 is wound about the pin 134 and the two ends of the coil spring 135 are 
mounted to the trigger 133 and the casing 131, respectively. The coil 
spring 135 urges the trigger 133 in such a direction that the lever 107 is 
opened. Normally, a trigger lock 130b provided on the safety lock 130 is 
in contact with a trigger edge 133b of the trigger 133 so as to restrict 
the action of the latter. 
A staple drive member 136 is disposed close to the top surface of the outer 
sleeve drive member 132 and a trigger receptacle 137 is provided at the 
proximal end of the staple drive member 136, with a trigger end 133a in 
the upper part of the trigger 133 being mounted to the trigger receptacle 
137. The casing 131 is also provided with an indicator lever 138 which is 
distally urged by means of an indicator spring 139, such that the action 
of the indicator lever 138 can be observed through an indicator window 
131a made in the casing 131. 
As shown in FIGS. 19 and 20, the insertion member 104 contains in it the 
following parts: the trocar drive member 128 extending through the center; 
a guide 128a for supporting the trocar drive member 128; the outer sleeve 
drive member 132 provided above the trocar drive member 128; and the 
staple drive member 136 in contact with the interior of the insertion 
member 104. The individual drive members are capable of moving back and 
forth independently of each other and in the interior of the head of the 
insertion member 109, the trocar drive member 128 is fixed to the trocar 
114, the staple drive member 136 to the staple pusher 123, and the outer 
sleeve drive member 132 to the outer sleeve 118. The anvil head 105 which 
is to be installed on the head of the insertion member 109 is provided 
with an anvil 111 having slots 111a for clinching staples 119 (see FIG. 
18A), tubular anvil shaft 112 for coupling the anvil head 105 to the 
trocar 114, and circular grooves 113 formed at the proximal end of the 
anvil shaft 112 and which are free to come into or out of engagement with 
the latches 117 (see FIG. 18c). 
Having described above the construction of the suturing apparatus according 
to the sixth embodiment of the invention, we now describe how it is 
operated. 
First, the anvil head 105 is inserted into an end of a tissue section of a 
tubular structure, say, the intestine and said one end is purse-string 
sutured around the anvil shaft 12. In addition, the insertion member 104 
of the main body 102 is inserted into the other end of the tissue section 
and said other end is also purse-string sutured around the outer sleeve 
118. 
Thereafter, the anvil shaft 112 is inserted into the trocar sleeve 15 using 
the trocar 114 as a guide, whereupon the leaf springs flex outwardly, 
causing the latches 117 to come into engagement with the circular grooves 
113 (see FIG. 20). If the slider switch 108 of the operating member 103 is 
moved distally, the slider latch 108a in the operating member 103 comes 
into engagement with the rod groove 124b on the rod 124 (see FIG. 21). 
In addition, the distal movement of the slider switch 108 will cause the 
outer sleeve drive member 132 to be moved distally, whereupon the outer 
sleeve 118 is moved distally to cover the leaf springs 116. In this state, 
the anvil head 105 will not be disconnected from the head of the insertion 
member 109 since the outer sleeve 118 will restrain the leaf springs 116 
from flexing outwardly (see FIG. 21). 
In the next step, the adjusting knob 106 of the operating member 103 is 
rotated, whereupon the rod 124 is gradually retracted toward the operator 
under the action of the rod screw 124a and the rotating screw 125. Since 
the trocar drive member 128 is fixed at the distal end of the rod 124, the 
anvil head 105 is moved toward the head of the insertion member 109. On 
this occasion, the distal edge 127a of the safety guide 127 comes into 
engagement with the indicator edge 138a, whereupon the indicator lever 138 
is actuated to give the operator a visual signal for the distance between 
the anvil head 105 and the head of the insertion member 109. At the same 
time, the outer sleeve 118 is retracted since the slider switch 108a is in 
engagement with the rod groove 124b (see FIG. 22). When the distance 
between the anvil head 105 and the head of the insertion member 109 has 
reached an appropriate value for performing anastomosis, the safety guide 
127 in the operating member 103 is moved toward the proximal end by means 
of the top surface 130a of the safety lock 130. If the safety lock 130 is 
rotated, the trigger edge 133b comes out of engagement with the trigger 
lock 130b and the operator can now grip the lever 107. 
If the operator grips the lever 107, the trigger 133 will rotate about the 
pin 134 and the trigger end 133a moves the trigger receptacle 137 
distally. Hence, a compressive force is transmitted through the staple 
drive member 136 and staple pusher 123 to reach the rod-shaped projections 
123a, which then cause staples 119 to be ejected form the staple channels 
120 and the ejected staples 119 are clinched by the slots 111a in the 
anvil 111. At the same time, the cylindrical cutter 121 severs the excess 
tissue of the intestine inside the staple line to complete the anastomotic 
operation (see FIG. 23). 
If the slider switch 108 of the operating member 103 is slid toward the 
operator 25, the anvil head 105 is moved toward the head of the insertion 
member 109 or after the end of adjustment of the distance between the 
anvil head 105 and the head of the insertion member 109 or at any other 
position of the anvil head 105, the slider latch 108a is disengaged from 
the rod groove 124a and the outer sleeve drive member 132 is move toward 
the operator. 
As a result, the outer sleeve 118 which has covered the leaf springs 116 
are moved toward the operator and the leaf springs 116 are now capable of 
flexing outwardly; in this state, the anvil head 105 can be disconnected 
from the head of the insertion member 109 and a new anvil head 105 can be 
installed on the head of the insertion member 109 (see FIG. 24). 
According to the sixth embodiment of the invention, the anvil head 105 can 
be fixed in position immediately after it is fitted to the head of the 
insertion member 109 and, hence, there is no possibility that the anvil 
head 105 is dislodged from the head of the insertion member 109 at an 
unintended position as the anvil head 105 is retracted toward the head of 
the insertion member 109. In addition, if any trouble such as twisting of 
the intestine occurs during adjustment of the distance between the anvil 
head 105 and the head of the insertion member 109, the anvil head 105 can 
immediately be disconnected form the head of the insertion member 109; 
thus, the medical suturing apparatus according to the sixth embodiment of 
the invention is very easy to manipulated. 
FIGS. 25 and 26 show a seventh embodiment of the invention and the 
structural parts which are identical to those employed in the sixth 
embodiment are identified by like numerals and will not be described in 
detail. The anvil shaft 112 of the anvil head 105 in the seventh 
embodiment does not have the circular grooves 113 which are provided in 
the sixth embodiment and, instead, the shaft 112 has external ribs 140 and 
internal ribs 144 which are formed on the inner surface of the shaft to 
project radially inwardly. 
The trocar sleeve 115 and the outer sleeve 118 used in the sixth embodiment 
are not provided within the head of the insertion member 109 according to 
the seventh embodiment; instead, the head 109 contains in it a rotating 
shaft 142 internally provided with a double thread 143 and a rotating 
shaft drive member 145 which transmits the rotation of the adjusting knob 
106 of the operating member 103 to the rotating shaft 142. 
In addition, a trocar 114 is provided that has slits 141 extending parallel 
to the axis of the insertion member 104. Further in addition, the slider 
switch 108 and the outer sleeve drive member 132 which are employed in the 
sixth embodiment are absent from the seventh embodiment. Except for these 
and other points described above, the seventh embodiment is essentially 
the same as the sixth embodiment. 
A modification of the seventh embodiment is shown in FIG. 27, in which the 
trocar 114 is externally provided with a double thread 145 to be rendered 
rotatable and an equivalent of the rotating shaft 142 is formed of a 
sleeve 147 having safety guides 146 and the internal ribs 144 are formed 
on the inner surface of the anvil shaft 112. 
When mounting the anvil head 105 to the head of the insertion member 109 in 
the seventh embodiment, the trocar 114 is inserted into the anvil shaft. 
112, with the internal ribs 114 in the anvil shaft 112 being in registry 
with the slits 141, until it contacts the distal end of the anvil shaft 
(see FIG. 26A). When the adjusting knob 106 of the operating member 103 is 
rotated, the rotation is transmitted to the rotating shaft 142 via the 
rotating shaft drive member 145. The rotation of the rotating shaft 142 as 
combined with the external ribs 140 in engagement with the double internal 
thread 143 causes the anvil head 105 to be slowly moved toward the head of 
the insertion member 109; however, the combined action of the internal 
ribs 144 and the slits 141 will prevent the anvil head 105 from rotating 
(see FIG. 26B). 
If the distance between the anvil head 105 and the head of the insertion 
member 109 is determined, the subsequent procedure will be the same as in 
the sixth embodiment. In the modification shown in FIG. 27, the rotation 
of the trocar 114 in engagement with the internal ribs 144 will retract 
the anvil shaft 112 such that the anvil head 105 is moved toward the head 
of the insertion head 109 while the external ribs 140 combine with the 
safety guides 146 to prevent the rotation of the anvil head 105. 
Because of these structural features, the seventh embodiment has the 
advantage that as soon as the anvil head 105 is installed on the head of 
the insertion member 109, it is secured against disconnection from the 
head 109. Since there is no possibility of the anvil head 105 to be 
dislodged accidentally during the anastomotic operation, the medical 
suturing apparatus of the invention can be manipulated efficiently. 
Similar results are attained in the modification of the seventh embodiment 
which is shown in FIG. 27. 
FIGS. 28 and 29 show an eighth embodiment of the invention and the 
structural parts which are identical to those employed in the sixth 
embodiment are identified by like numerals and will not be described in 
detail. According to FIG. 28, there are provided within the head of the 
insertion member 109 a plurality of holes 150 made in the bottom 121a of 
the cylindrical cutter 121 and latching sleeves 148 which have a larger 
inside diameter than the holes 150 and which are arranged coaxially with 
said holes 150. 
Each hole 150 has a hole edge 150a formed on the inner circumference. The 
staple pusher 123 is provided with arrow-shaped latches 149 fixed 
coaxially with the latching sleeves 148 and each of the arrow-shaped 
latches 149 has fingers 149a. The cylindrical cutter 121 is adapted to be 
capable of moving back and forth relative to the staple pusher 123 in the 
axial direction of the head of the insertion member 109. Except for these 
and other points described above, the eighth embodiment is essentially the 
same as the sixth embodiment. 
Description is therefore made of only the action of ejecting the 
cylindrical cutter 121. In the initial state (see FIG. 28A), the operator 
grips the lever 107 of the operating member 103, whereupon the staple 
pusher 123 is urged distally. Then, the arrow-shaped latches 149 are 
inserted into the holes 150 and the fingers 149 come into engagement with 
the bottom 121a of the cutter 121, causing the latter to be moved distally 
(see FIG. 28B). 
If the operator continues to grip the lever 107, the staple pusher 123 is 
further moved distally and the continued action of the arrow-shaped 
latches 149 will keep the cylindrical cutter 121 moving. When the blade of 
the cylindrical cutter 121 contacts the washer (not shown) on the anvil 
head side, the developing resistance will cause an elastic deformation of 
the arrow-shaped latches 149, which then pass through the holes 150 to 
enter the latching sleeves 148 (see FIG. 28C). 
After firing the staples 119, the operator stops gripping the lever 107, 
whereupon the staple pusher 123 is retracted toward the operator. Since 
the fingers 149a of the arrow-shaped latches 149 come into engagement with 
the hole edges 150a in the latching sleeves 148, the cylindrical cutter 
121 is also retracted toward the operator (see FIG. 29A). 
When the operator grips the lever 107 again, the staple pusher 123 is moved 
distally and so are the arrow-shaped latches 149. Because of their shape, 
the moving latches 149 slide along the inner surfaces of the latching 
sleeves 148 to eventually pass through them, so the cylindrical cutter 121 
will not project from the head of the insertion member 109. Since the 
arrow-shaped latches 149 are positioned on the distal end of the latching 
sleeves 148, no part of the cylindrical cutter 121 will be exposed as such 
from the head of the insertion member 109 (see FIG. 29B). 
The conventional medical suturing apparatus have had a safety problem in 
that if the lever is gripped after firing of the staples, the cylindrical 
cutter will be ejected. However, this problem is absent from the suturing 
apparatus according to the eighth embodiment since the cylindrical cutter 
121 will not be ejected even if the lever is gripped after use in 
anastomosis. 
FIGS. 30 to 32 show a ninth embodiment of the invention and the structural 
parts which are identical to those employed in the sixth embodiment are 
identified by like numerals and will not be described in detail. As shown 
in FIGS. 30A and 30C, the suturing apparatus according to the ninth 
embodiment has a trigger lock 155 provided on the trigger edge 133b within 
the operating member 103 in such a way that it is free to rotate about a 
pin 154 while it is urged with a coil spring 153. 
The lead of the insertion member 109 is shown in FIG. 30B; leaf spring 
latches 156 are normally provided on selected inner surfaces of the staple 
channel casing 122 in such a way that they are elastically deformed by the 
outer circumference of the cylindrical cutter 121. Except for these and 
other points described above, the ninth embodiment of the invention is 
essentially the same as the sixth embodiment. 
As in the sixth embodiment, if the distance between the anvil head 105 and 
the head of the insertion member 109 has reached an appropriate value for 
anastomosis, the safety lock 130 can be released. If the operator grips 
lever 107, staples 119 are expelled and clinched by the slots 111a in the 
anvil 111. At the same time, the cylindrical cutter 121 is ejected to cut 
the excess tissue inside the staple line, whereby the anastomotic 
operation is completed (see FIG. 31B). 
The state within the operating member 103 after the firing of staples 119 
is shown in FIGS. 31A and 31C. If the operator grips the lever 107, the 
trigger 133 is rotated about the pin 134, whereupon the trigger lock 155 
which has been in engagement with the trigger edge 133b rotates about the 
pin 154 under the elastic force of the coil spring 153. FIG. 31C shows the 
trigger lock 155 disengaged from the trigger edge 133b. 
If the operator releases the grip on the lever 107, the trigger 133 will 
tend to revert to the initial state (i.e., before the expelling of 
staples) under the elastic force of the coil spring 135. In fact, however, 
the trigger lock 155 has rotated under the elastic force of the coil 
spring 153, so the trigger 133 will rotate without being stopped by the 
trigger edge 133b and, as a result, the trigger receptacle 137 will be 
moved toward the operator (see FIG. 32A). 
The trigger receptacle 137 is provided on the staple drive member 136, so 
needless to say, the staple drive member 136 and the staple pusher 123 
within the head of the insertion member 109 are also moved toward the 
operator and so is the cylindrical cutter 121 fixed to the staple pusher 
123. FIG. 32B shows the staple pusher 123 as it has been moved toward the 
operator; obviously, the leaf spring latches 156 which were elastically 
disposed on the outer circumference of the cylindrical cutter 121 before 
firing of the staples 119 flex inwardly since the cylindrical cutter 121 
has moved to the retracted position. 
The suturing apparatus of the ninth embodiment of the invention has the 
advantage that even if the lever 107 is gripped after the firing of the 
staples 119, the leaf spring latches 156 will contact the blade of the 
cylindrical cutter 121 to thereby prevent it from projecting beyond the 
head of the insertion member 109. This is also the case with the staple 
expelling rod-shaped projections 123a since they are provided on the 
staple pusher 123 to which the cylindrical cutter is fixed (see FIG. 32C). 
Thus, in addition to the advantages of the eighth embodiment, the suturing 
apparatus of the ninth embodiment offers an advantage in safety in that 
the rod-shaped projections 123a which are direct means of firing the 
staples 119 will not protrude from the head of the insertion member 109. 
Even if the lever 107 being withdrawn from a section of the intestine is 
gripped inadvertently, the normal tissue will not be affected at all. 
As described on the foregoing pages, the medical suturing apparatus 
according to the first aspect of the invention has an anvil head provided 
at the distal end of the main body and a staple head having a plurality of 
staples disposed therein is provided in a position opposed to the anvil 
head and this offers the advantage that even if the lever is gripped when 
performing anastomosis on tubular structures such as the intestine and 
esophagus, no staples will be expelled from the staple head or the cutter 
will not be ejected unless the staple head is installed at the distal end 
of the main body. Therefore, the unnecessary firing of staples and the 
hazard of the cutter are significantly reduced. In addition, the running 
cost of hospitals is also reduced by using the main body repeatedly after 
replacing the staple head by a new one. 
According to the second aspect of the invention, there is provided a 
medical suturing apparatus in which an anvil head can be fixed in position 
immediately after it is installed on a trocar at the distal end of the 
insertion member when performing anastomosis on tubular structures such as 
the intestine and esophagus. Hence, there is no possibility that the anvil 
is dislodged in an unintended position as it is moved toward the head of 
the insertion member. In addition, the manipulability of the suturing 
apparatus is improved since the anvil head can be disconnected as soon as 
there occurs a trouble such as twisting of the intestine during adjustment 
of the distance between the anvil head and the head of the insertion 
member. Further in addition, the cylindrical cutter will not project from 
the head of the insertion member even if the lever of the operating member 
is inadvertently gripped after the firing of staples. This is a salient 
advantage in safety since no part of the normal tissue will be damaged by 
the suturing apparatus being withdrawn from the intestine.