Note: Descriptions are shown in the official language in which they were submitted.
1136~20
PRECISELY ALIGNED ANASTOMOSIS
STAPLING CARTRID~E AND INSTRUMENT
Background of_the Invention
Field of the Invention
This invention relates to surgical instru-
ments, in general, and to an instrument using a pre-
cisely aligned disposable cartridge for surgical
stapling of hollow body organs, in particular.
Descri~tion of the Prior Art
Presently in the prior art, several instru-
ments are known for circular joining by staples of
hollow body organs. United St~tes Patents Nos.
B 3,638,652, 3,552,626, 3,388, ~ and 3,193,165 all
relate to instruments of this type, which are useful
in surgical procedures involving the colon and the
esophagus. Despite the fact that these instruments
are known in the prior art, they have never been
introduced into clinical use in the United States.
These instruments, which are disclosed in the afore-
mentioned patents, have the important drawback of
requiring hand loading of the suturing staples into
the staple magazine of the instrument after each use
of the instrument. This means that once the instru-
ment is actuated and its staples ejected and clinched,
it must then be cleaned before the magazine can be
manually refilled with staples. While being refilled,
the instrument, of course, is inoperative and may not
be further used in the on-going surgical operation.
The aforementioned U.S. Patent No. 3,552,626 discloses
a form of the instrument in which the staple magazine
and associated anvil of the instrument are interchange-
able so that different sizes may be mounted on the
same instrument body, but this arrangement is solely
11 3 ~ ~
for the purpose of accommodating hollow body organs of
different sizes.
Summary of the Invention
The present invention is directed to an
instrument of the type generally described and was
developed to overcome the drawbacks and disadvantages
which one experiences when attempting to use similar
instruments according to prior art teachings and, most
notably, those teachings which are contained in the
aforementioned patents. One of the principal benefits
results from providing the staple carrying cartridge
part and the staple clinching anvil part as disposable
elements and, thus, the staple forming parts, which
are subject to wear from usage and/or damage from
cleaning and storage, are furnished as new parts for
each stapling procedure. The parts most likely to
wear or damage are the pusher fingers, which eject the
staples from the cartridge and the anvil, against
which the staple legs are clinched or formed. Addi-
tionally, successive uses of an instrument during a
surgical procedure are easily attained simply by
detaching a spent cartridge and replacing with a fre~h
cartridge. Keying of the parts of the disposable
cartridge to each other and to the body of the instru-
ment is also a feature of the invention to insure that
all parts are in the correct orientation and properly
indexed; hence, when the instrument is actuated, the
staples are ejected through the tissue of the hollow
body organ and clinched to effect the desired staple
line.
The present invention provides an instrument
for effecting end-to-end anastomoses, side-to-side
anastomoses, or end-to-side anastomoses by means of a
pair of concentric circles of staples to ensure a high
margin of security in maintaining the desired tissue
joining. The present invention, further provides a
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unique disposable cartridge, and a precise cooperation
between the cartridge, the anvil and the instrument
for staple forming alignment. Variations in staple
dimensions and array patterns are easily provided by a
variety of cartridge designs. Unique provision is
made for easy removal of the instrument from the
stapled anastomosis. Further, the interior of the
stapling mechanism is generously vented to prevent the
build up of excessive pressure in the tissue confined
within the stapling mechanism while the tissue is
being compressed and clamped prior to and during the
actual firing of the staples and the excision of the
excess tissue in the lumen of the anastomosis.
Brief Description of the _everal Views of the ~rawings
Further advantages and details of the present
invention will become more evident from a consideration
of the following descriptive text, when taken in
conjunction with the appended drawings in which:
Figure 1 is a top plane view cut through the
trigger of an embodiment of the surgical stapling
instrument with the bayonet in the unlocked position.
Figure 2 is an enlarged plan view showing
the pivot pin structure in section taken along lines
2-2 of Figure 3.
Figure 3 is a side elevation of the instru-
ment of Figure 1.
Figure 4 is a longitudinal section through
the body of the instrument of Figure 1.
Figure 5 is a cross section through the
pivot pin of Figure 4.
Figure 6 is a perspective view of the pusher
hub.
Figure 7 is a longitudinal section of the
instrument of Figure 4.
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Figure 8 is a cross section through the
pivot pin of Figure 7 with the trigger in elevation.
Figure 9 is a side elevation of an second
embodiment of the disposable cartridge showing the
anvil-carrying and staple-carrying parts.
Figure 10 is a top plan of the staple-
carrying part of Figure 9 and the front of instrument
of Figure 1 with the bayonet sleeve in section.
Figure 11 is an enlarged side elevation of
the staple-carrying part and front of instrument with
the bayonet mounting structure in section.
Figure 12 is a top plan view of the staple-
carrying part locked onto the instrument of Figure 3.
Figure 13 is a side elevation of the struc-
ture illustrated in Figure 12.
Figure 14 is a sectional view of the bayonet
assembly in the unlocked position as viewed along
lines 14-14 of Figure 12.
Figure 15 is the same view as Figure 14 but
with the bayonet assembly in the locked position.
Figure 16 is a side elevation of the staple-
carrying part of Figure 9 with the main body part in
section.
Figure 17 is a sectional view taken along
lines 17-17 of Figure 16.
Figure 18 is a bottom plan view of the
staple-carrying part of Figure 9 with a portion of the
main body part in section.
Figure 19 is a longitudinal section through
the front end of the instrument illustrated in Figure
1.
Figure 20 is a bottom plan view of a portion
of the rod and driver tube for the embodiment illu-
strated in Figure 1.
Figure 21 is a front end view of the struc-
ture illustrated in Figure 20.
Figure 22 is a front elevation o~ the fully assembled
st~ple-car~yin~ part of Figure ~.
Figure 23 is a sectional view taken along lines 23-23
5of Figure 22.
Figure 24 is a partial section taken along lines 24-24
of Figure 23.
10Figure ~5 is a front elevation as viewed along lines
25-25 of Figure 23.
Figure 26 is a rear elevation of the pusher back il-
lustrated in Figure 25.
Figure 27 is a partial section through one of the vent
holes of the pusher back of Figure 25.
Figures 28 through 30 whichare on the same sheet as
20Figure 22, show the details of the staples.
.
Figure 31 which is on the same sheet as Figure 9, is
a longitudinal section of the knife and support ring.
Figure 32 which is on the same sheet as Figure 9, is
a partial plan view of the structure illustrated in Figure 31.
Figure 33 which is on the same sheet as Figure 9, is
a sectional view of the tip of the knife of Figure 31.
Figure 34 is a longitudinal section of the anvil-carry-
ing assembly of Figure 9.
~ Figure 35 is an end plan view of the anvil-carrying
assembly of Figure 34.
Figure 36 is a sectional view taken along lines 36-36
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4A.
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of Figure 35 with the staples added.
Figure 37 is a plan view of a portion of the anvil
of Figure 34.
Figure 38 is a sectional view taken along lines 38-38
of Figure 36.
Figure 39 is a partial front elevation as viewed along
lines 39-39 of Figure 34.
Figure 40 is a schematic view to show the detail of
the top indexing key of the anvil of Figure 34.
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113~
Figure 41 is a schematic view to show the
detail of the bottom indexing key of the anvil of
Figure 34.
Detailed Description of the Drawings
Referring now to Figures 1 through 41, a
preferred embodiment of the instrument with disposable
cartridge is depicted. As shown in Figures 1 through
8, the instrument comprises a main body or housing 310
defining a throughbore 311 and having an integrally
formed rear handle part 312. Projecting from the body
310 is a handle part 314, pivotably mounted to the
body 310 by means of pivot pin assembly 316. The
handle part 312 is received in the palm of the hand of
the operator and the handle part 314 is grasped by the
fingers of the same hand. When the fingers are squeezed
toward the palm, handle part 314 is pivoted about pin
316 and brought toward handle part 312. A safety bar
318, terminating in a knob 320 is pivotally mounted on
a pin 322 set into the body 310, and serves as a
safety to prevent the accidental actuation of handle
part 314 as shown by the arrow in Figure 3. As best
seen in Figure 4, a set screw 323 is received in a
B threaded bor~325, contained in handle part 314. The
set screw is adjusted and secured by a suitable adhesive,
so that the safety bar 318 can move into a locked
position without binding on its flat face 321.
Projecting from the forward end of the body
or housing 310 is an outer tube 330 which extends
forwardly and terminates at a substantial distance
from housing 310. Received on the remote end of tube
330, as best seen in Figure 9, is a disposable cart-
ridge referred to generally by the reference numeral
340. Attachment of disposable cartridge 340 to the
tube 330 is effected by means of a bayonet-connecting
sleeve 342 (Figure 35) in a manner which will be
~36020
described hereinafter. This disposable cartridge 340
comprises a staple-carrying member 344 and an anvil-
carrying member 346.
; With reference to Figures 3 through 8,con-
centrically mounted within the tube 330, is a driver
tube 350 and a rod 352. Driver tube 350 reciprocates
within tube 330 and serves as a pusher for ejecting
staples; the rod 352 reciprocates independent of
driver tube 350 and serves to position the anvil-
carrying member 346 relative to the staple-carrying
member 3~4. The rod 352 extends entirely through the
instrument with one end projecting out of the front of
the instrument to receive and carry the anvil-carrying
member 346 and the other end projecting out of the
back of the instrument for receiving a wing nut 360.
The rear end of the rod 352 is threaded and is in
threaded engagement with an internally threaded sleeve
extension 410 of wing nut 360.
As shown in Figures 4 and 7, an end cap 362
is applied to the rear of the instrument and effects a
closure of throughbore 311. Cap 362 secures stepped
bushing 704 against shoulder 706 in throughbore 311.
The smallest bore through bushing 704 supports reduced
part 406 of the rod 352. The cap 362 contains an
external thread that coacts, or threadedly engages,
with the thread formed in the terminal part of through-
bore 311. ~ ~
R Referring now to Figures ~ through~, the
V internal arrangement for the body or housing 310 will
now be described in detail. As already noted, the cap
362 contains an external thread which threadedly
engages with an internal thread suitably formed in the
terminal part of the throughbore 311. This threaded
engagement is identified generally by the reference
numeral 366. Throughbore 311, at its end proximal to
the disposable cartridge mounting, receives the outer
il36020
tube 330 which extends into the throughbore 311 ter-
minating at the entry to an enlarged region 370 of the
bore 311. The body 310 and the tube 330 are rigidly
interconnected in the bore 311 by holding pin 361, so
that there is no relative motion between them. The
driver tube 350 extends coaxially within the sleeve
330 and projects therefrom into the enlarged region
370 whereupon it is fixedly mounted at its end within
a pusher hub 372. This hub 372, in turn, is connected
by means of threads 376 with a pusher-stop cap 378.
The driver tube 350, together with the pusher hub 372
and the cap 378~ all move as a unit.
With reference to Figures 4 and 6, the
pusher hub 372 is of generally cylindrical shape with
a stepped throughbore 371~ The larger portion 373 of
the bore 371 receives and mounts the reduced end of
the driver tube 350. The smaller portion 375 of the
bore 371 is of sufficient diameter to allow the rod
352 to freely slide therethrough. Cutout portions 380
are provided on diametrically opposed sides of the hub
372. These cutouts cooperate with the trigger 314 in
a manner described hereinafter to serve as the means
by which the driver tube 350 is reciprocated within
the outer tube 330 of the instrument.
The arrangement for reciprocating the driver
tube 350 is illustrated best in Figures 4 through 7.
As already noted, the pusher hub 372 carries the
cutouts 380 on diametrically opposed sides. The
handle part 314 is provided at its lower end with a
yoke 390, the legs of which are identified by the
reference numeral 392. These legs 392 are received in
the cutouts 380, each of which contains a front wall
391 and a back wall 393.
Pivoting of trigger 314 about pin 316 results
in a longitudinally-directed force being exerted on
the front walls 391 of the hub 372 by yoke portion 390
of the trigger 314. This results in the forward
1 1 3~V~3
movement of driver tube 350 within outer tube 330. A
spring 356 received around tube 350 in region 370
biases hub 372 against the foward movement produced by
handle part 314. The left end of spring 356, as
viewed in Figure 7, is held against the end of tube
330.
The rod 352 extends completely through the
tube 330 and body 310 of the instrument. The rod is
provided with a reduced portion 400 bounded at its
rearend by bevelled shoulder 402. Provided near the
front of the reduced portion 400 is an indicator
groove 403. A groove 405 connects the main portion of
the rod with a reduced portion 406, which, in turn, is
connected to a threaded reduced portion 408 via a
groove 707.
The wing nut 360, which appears at the rear
of the instrument, is provided with a sleeve extension
410. The nut 360 is secured to the sleeve extension
by a pair of pins 412. A retaining ring 424 is received
into a groove 413 for the purpose of securing the wing
nut 360 and its sleeve extension 410 onto the end cap
362. The sleeve extension 410, as well as nut 360,
defines a throughbore through which rod 352 passes.
The front portion of the bore within the sleeve exten-
sion 410 is threaded to threadedly engage with the
threads defined on the reduced portion 408 of the rod
352. By the arrangement described, when the ~ap 362
is threaded into the body 310 with the wing nut 360
held thereon by means of the retaining ring 424, the
wing nut 360 will not translate when rotated because
of being secured to the end cap 362 in the manner
described. Accordingly, sleeve extension 410, acting
as a nut on threaded part of rod 408, will cause the
rod 352 to reciprocate.
The shoulder 401 of reduced portion 406 acts
as a stop working against a shoulder 430 defined in
the bushing 704. The furthest position of the rod
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--10--
352, that it may assume when driven to the right by
means of sleeve extension 410, is illustrated in
B Figure ~ with the shoulder 401 and the shoulder 430
in contact. This also represents the closest approach
of the anvil-carrying part 346 to the staple-carrying
part 344 of the disposable cartridge. This position
of closest approach is illustrated in Figure 7 and is
selected to define a space between the two parts of
the disposable cartridge that is egual to the minimum
spacing required to accommodate tissue from whatever
hollow body organs are to be stapled by the instrument
of the present invention.
With reference to Figures 9 through 27, the
staple-carrying part 344 is an assembly comprised of a
hollow main body portion or shell 440 having a cylindri-
cal portion and a frusto-conical portion which terminates
in a small diameter neck 441. As best seen in Figure
18, a staple guide member 448 provided with a projec-
tion 452 coacting with a slot 450 defined on the main
body part 440 for rotational orientation is secured to
the main body part 440. The guide member 448 forms a
guide face 456 which defines two concentric circular
series of spaced staple-receiving slots 458, see
Figure 22. Holes 451 provide venting for the staple-
carrying part 344. Received within the main body part
440, as shown in Figures 18 and 23, is a staple pusher
assembly 460, which fits concentrically within the
main body part 440. The rear portion of the staple
ejection assembly 460 is defined by a pusher back 453
having a generally frusto-conical shape and containing
vent holes 463. The forward portion of the staple
pusher 460 is defined by a member 455 which contains
two concentric rings of peripherally spaced fingers
462, each one of which is received within a staple
receiving slot 458. The member 455 is secured to the
pusher 453 by a suitable adhesive at a point 457. The
rear end 461 of the staple pusher 4~3 is adapted to be
1136~ 0
contacted by the end of driver tube 350. Hence, upon
advancing the staple pusher assembly 460 by driver
tube 350, the fingers 462 will pass further into the
staple receiving slots 458, pushing staples contained
therein axially outwardly. The staple pusher 460 is
reinforced with a plurality of ribs 464 (Figure 25),
at least two of which are provided with suitable
plastic projections or bosses 466. With reference to
Figures 22 and 31 through 33, a knife 468 in the form
of an open cup with the rim defining the knife edge
470 is mounted within the staple ejector assembly 460
by means of holes 473 through which the bosses 466
project. In mounting, the bosses 466 are "hot staked"
to fasten the knife 468 onto a support ring 467 of the
the staple ejector assembly 460 so that advancement of
the staple ejector 460 also advances knife 468. The
knife 468 has vent holes 461 which communicate with
the vent holes 463 in the pusher 453.
As best seen in Figures 16 through 19, a
shell support liner 576 of generally cylindrical shape
is press fitted into the end of the small diameter
neck 441. The liner 576 contains a pair of bayonet
projections 578 and a guide projection 580, all of
which mate with slots 581-583, respectively, to ensure
proper indexing of the liner 576 when it is fitted
into the neck 441. Defined within the liner 576 is a
tube bore 584 of predetermined depth and which is of
sufficient diameter to be slidably mounted on the
flanged end of tube 330. Contained within the liner
576 is a keyway 586, which mates with key 588 to
ensure proper orientation of the staple-carrying part
344 with respect to the tube 3~0. An additional bore
710 of smaller diameter than bore 584 is provided for
in liner 576; bore 710 is of sufficient diameter to
allow tube 350 to freely slide therethrough. Bore
710, as viewed in Figure 17, contains a pair of inwardly
extending support members 686, which pass through
il3~0~0
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slots 353 (Figures 10 and 20) in pusher rod 350. The
inner ends of members 686 define both a diameter 689
which fits closely with rod 352, and two keys 687 and
688 which mate respectively with slots 458 and 459 in
rod 352. The keys, 687 and 688, and the slots 458 and
459, are of two different widths so that there is only
one position in a 360 rotation in which the parts can
be assen~led.
It is paramount that the anvil 530 be in
precise alignment with cartridge part 344 in all
respects. In the above construction, the cartridge is
aligned and keyed to center rod 352. As will be
explained below, the anvil 530 is also aligned and
keyed to the same slots 458 and 459 in rod 352. since
rod 352 is the single member connecting cartridge 344
and anvil 530 during the stapling procedure, an align-
ment path through the least number of parts (in order
to obtain a minimum build up of error through accummu-
lated tolerances, clearances, etc.~ has been provided.
When the staple-carrying part 344 of the
disposable cartridge 340 is assembled onto the end of
the outer tube 330 by means of bayonet-connecting
sleeve 342 and the bayonet pins 578 of the main body
part 440 as shown in Figures 10 through 15, the main
body part 440 will be drawn to a position such that
the staple ejector 460 will engage the free end of the
driver tube 350 and then be moved slightly outwardly
relative to the main body part 440. The staple-carrying
part 344 will then be ready for use.
The anvil-carrying part 346 is illustrated
in Figures 9 and 34 through 41, inclusive, and comprises
a body portion 510 of cup shape with a central hub 512
defining a knob-receiving bore 514 and "D" shaped bore
566. A knob 516 is received within the bore 514. A
skirt 568, defined by the hub 512, projects over the
bore 514 and engages the shoulder defined by the
reduced section 522 to hold knob 516 captive in bore
113~
-13-
514, but allowing it to rotate freely. A longitudinal
bore 570 is provided in the knob 516. The bore 570,
at its forward portion, contains internal threading
520, which matches the threading at the end of rod
352. The bore 566 contains an inner flat portion 565
to accommodate the flat 500 at the end of rod 352.
Holes 349 provide venting for the anvil carrying part
346. Metal anvil 530, having two concentric circular
arrays of spaced staple-clinching grooves 532 and a
central hole 533, is mounted onto body portion 510 by
press-fitting. The central hole 533 has the same
cross-sectional configuration as the "D" shaped bore
566. Outwardly projecting keys 541, 542 mate with
slots 458, 459, respectively, on rod 352 to further
ensure proper orientation of the anvil-carrying part
346 with the rod 352. The keys 541, 542 are of dif-
ferent widths so that there is only one position in a
360 rotation which will permit assembly. Thus the
anvil 530 is keyed to rod 352 and slots 45~, 459
therein in the same manner as is staple-carrying part
344. To emphasize, this constructicn provides a
minimum build up in tolerances and clearances in the
assembly path connecting the an~il and the staple-
carrying part when the staples are formed.
Anvil 530 supports a cutting block 544 of
annular configuration, that cooperates with knife 468.
Cutting block 544 is rubber, soft plastic, or the
like. Anvil 530 has vent holes 347 which communicate
with vent holes 349 in body 510.
In operation, wing nut 360 is rotated to
advance rod 352 out from the end of tube 330. A
staple-carrying part 344 of a disposable cartridge 340
is fitted over rod 352 and tube 330 and attached to
tube 330 by a bayonet mount which includes bayonet
pins 578 in the cartridge 340 and bayonet-receiving
slots 357 in the sleeve 342. As shown in Figures 10
through 15, bayonet-connecting sleeve 342 is slidably
1136(~ZO
-14-
mounted on tube 330. A cutout portion 341 of sleeve
342 and a pin 343 in tube 330 ensure the proper orienta-
tion of the sleeve 342 when it is slidably mounted on
tube 330. A retaining ring 345, mounted in a groove
on the tube 330 and a wall 747 in the sleeve 342,
limit the return movement of the sleeve 342. A wall
349, defined by the flanged portion 351 of the tube
330 and a wall 353, defined by sleeve 342 in coopera-
tion with spring 756 bias sleeve 342 rearwardly to
hold cartridge 340 firmly against end of tube 351.
Next, the anvil-carrying part 346 is assembled
onto the end of projecting rod 352. To this end, the
knob 516 is grasped and the threaded end of rod 352 is
introduced into the hole 570 having threaded portion
520. Flat 500 of rod 352 is received at this time in
"D" hole 565 of anvil 510 before the threading engages,
whereafter, knob 516 is rotated to seat threaded end
of rod 352 into the threaded portion 520 of hole 570
and draw the flat 500 into the "D" hole 565. Keys
541, 542 assure that staple-carrying slots 458 and
staple-clinching grooves 532 are optimally aligned.
As previously explained, keys 541, 542 are differently
sized so that anvil 530 cannot be positioned 180 out of
rotational alignment. Wing nut 360 is then rotated to
retract rod 352 and thus bring anvil-carrying part 346
close to staple-carrying part 344.
In this condition, the instrument is inserted
into the patient through the hollow organ that is to
be stapled. At this time, the patient has been prepared
such that the hollow organ to be stapled has been cut
and there are two cut ends to be joined together by
means of the instrument of the present invention. The
instrument is inserted through the hollow organ until
it projects from one of the cut ends. The wing nut
360 is rotated to extend the rod 352, thereby creating
a substantial gap between the anvil carrying part 346
and the staple carrying part 344.
113~
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Now, the cut end of the hollow organ, through
which the instrument is protruding, is fashioned with
a drawstring suture and drawn over the staple-carrying
part 344 about the rod 352. The other cut end of the
hollow organ is pulled over the anvil-carrying part
346 and, by means of a drawstring suture, is tied
closely about the rod 352. Thus, the two cut ends of
the hollow organ will be interposed between the anvil
part 346 and the staple-carrying part 344. At this
time, the wing nut 360 is rotated to cause retraction
of the rod 352, whereupon the anvil-carrying part 346
will be brought into close proximit~ with the staple-
carrying part 344. Wing nut 3~0 is turned until
marker ring 403 on rod 352 lies within the width of
marker 404 on body 310. These marks have been pre-
established to ensure that the tissue is clamped to a
thickness which can be satisfactorily joined by the
staples being used. The maximum clamping of tissue
interposed between the staple-~arrying part 344 and
the anvil-carrying part 346 exists when shoulder 401
of rod 352 abuts shoulder 430 of bushing 704.
At this time, the rod 352 will occupy a
position within the body 310 of the instrument, either
as shown in solid lines in Figure 7 with the stop 401
bearing against the stop 430, or due to a greater than
minimum thickness of entrapped tissue, the stop 401
will be axially displaced off of the stop 430 to the
left, as shown in phantom.
With the apparatus in the condition
described, that is, with the cut ends of the hollow
organ to be stapled drawn around the two disposable
parts of the cartridge, the safety 318 is released by
pivoting away from the handle part 314 toward the
handle part 312 in the manner shown in Figure 3, and
the handle is grasped with the handle part 312 resting
in the palm of the hand and the fingers curled about
the handle part 314. When the fingers are drawn
il3~i02()
-16-
toward the plam of the hand in the manner of making a
fist, the handle part 314 will be rotated about its
pivot pin 316 clockwise, as shown in Figure 7, toward
the handle part 312. This causes the yoke 390 to
advance the pusher hub 372 axially to the left, as
shown in Figuxe 7, and as indicated by the arrow.
This action will force the driver tube 350, which is
mounted into the hub 372 to the left as viewed in
Figure 7, against the biase of spring 356. Advance-
ment of driver tube 350 will, in turn, produce an
advancement of the staple pusher 460, since the rear
end 461 of this part is in contact with the end of the
driver tube 350. Advancement of the staple pusher 460
will cause the fingers 462 to move through the respec-
tive slots 458 ejecting the staples 159 contained
therein. The action of the fingers 462 against the
staples 159 is depicted in Figures 18 and 36; the
B forward faceS~Iof the fingers 462 are all provided with
a V-groove ~ in which the crossbar of the U-shaped
staple 159 is received. This assures a better contact
between the finger 462 and the staple 159 during
ejection.
Referring to Figures 16, 18, and 36 through
39, the action that takes place during ejecting of the
s~aple 159 is generally depicted; as the staples 159
are advanced or ejected out from the slots 458, they
are contacted by grooves 532 of the anvil 530 and bent
into a conventional B-shape, as depicted in Figure 38.
Simultaneously with the advancement of the staple
pusher 460, the knife 468, which is carried by the
staple pusher 460, is axially advanced toward the
anvil-carrying part and the knife edge 470 of the
knife 468 will intersect with the interposed tissue
ends of the trapped hollow organs. The cutting edge
470 of the knife 468, which is circular in configura-
tion, cuts through the tissues of the hollow organs
and into the annular cutting block 544, which is held
1~36~ZO
-17-
within the anvil as previously described. The driver
tube 350 will travel whatever distance is necessary to
bend the staples always into the same configuration.
There is, of course, a maximum limit to tissue thick-
ness which a specific staple length can accommodate as
shown by marks 404 and 403.
The excess portion of the ends of the hollow
organ to be joined are severed by the action of knife
edge 4~0. The vent holes 347 in anvil 530, and vent
holes 449 formed in the body 510, as well as vent
holes 451, 461 and 463 in the staple-carrying portion
344, allow for relief of gas, fluid or excess tissue
trapped within the instrument on account of the proce-
dure of stapling. The severed ends of the hollow
organ are retained around rod 352 and ~etween the
anvil-carrying part and the staple-carrying part.
The next step in the procedure would be to
rotate wing nut 360 to increase the spacing between
the anvil-carrying part and the staple-carrying part
to allow the stapled part of the hollow organ to be
withdrawn from between these instrument parts and
passed over the anvil-carrying part 346, so that the
instrument may be withdrawn. To this end, the anvil
carrying part 346 is provided with an external configu-
ration typically of spherical dish-shape to facilitate
the removal of the stapled organ from ~etween the two
parts 346 and 344 and passing of the stapled part of
the organ over part 346. The removal is best accom-
plished when the perimeter of the profile, in section
through the axis as shown in Figure 34, of the anvil-
carrying part 346 is equal to or less than the circum-
ference of the inner ring of staples represented by
the inner circular array of spaced staple clinching
grooves 532 in Figure 35.
Although the present invention has been
shown and described in terms of a preferred embodiment,
1136020
-18-
it will be appreciated that various changes may be
made without departin~ from the spirit of the concept.
