Apparatus for applying surgical fasteners

An apparatus is provided for applying surgical fasteners to body tissue. The apparatus has a handle assembly and an elongated body which extends distally from the handle assembly. A fastener applying assembly is operatively associated with a distal end of the elongated body and includes a cartridge housing a plurality of staples and an anvil movable between an open position and a closed position. An actuation assembly is configured to translate through the fastener applying assembly to effect progressive closure of the anvil and concomitantly effect sequential ejection of staples from the cartridge.

BACKGROUND 
1. Technical Field 
The apparatus relates to a surgical stapling apparatus, and more 
particularly, to an apparatus for sequentially applying a plurality of 
surgical fasteners to body tissue and optionally incising the fastened 
tissue. 
2. Background of Related Art 
Surgical devices wherein tissue is first grasped or clamped between 
opposing jaw structure and then joined by means of surgical fasteners are 
well known in the art. In some instruments a knife is provided to cut the 
tissue which has been joined by the fasteners. The fasteners are typically 
in the form of surgical staples however, two part polymeric fasteners are 
also utilized. 
Instruments for this purpose can comprise two elongated members which are 
respectively used to capture or clamp tissue. Typically, one of the 
members carries a disposable cartridge which houses a plurality of staples 
arranged in at least two lateral rows while the other member comprises an 
anvil which defines a surface for forming the staple legs as the fasteners 
are driven from the cartridge. Generally, the stapling operation is 
effected by a pusher which travels longitudinally through the cartridge 
carrying member, with the pusher acting upon the staples to sequentially 
eject them from the cartridge. A knife may travel with the pusher between 
the staple rows to longitudinally cut and/or open the stapled tissue 
between the rows of staples. Such instruments are disclosed in U.S. Pat. 
Nos. 3,079,606 and 3,490,675. 
A later stapler disclosed in U.S. Pat. No. 3,499,591 applies a double row 
of staples on each side of the incision. This is accomplished by providing 
a cartridge assembly in which a cam member moves through an elongate guide 
path between two sets of staggered staple carrying grooves. Staple drive 
members are located within the grooves and are positioned in such a manner 
so as to be contacted by the longitudinally moving cam to effect ejection 
of the staples. Other examples of such staplers are disclosed in U.S. Pat. 
No. 4,429,695. 
Each of the instruments described above were designed for use in 
conventional surgical procedures wherein surgeons have direct manual 
access to the operative site. However, in endoscopic or laparoscopic 
procedures, surgery is performed through a small incision or through a 
narrow cannula inserted through small entrance wounds in the skin. In 
order to address the specific needs of endoscopic and/or laparoscopic 
surgical procedures, endoscopic surgical stapling devices have been 
developed and are disclosed in U.S. Pat. Nos. 5,040,715; 5,312,023; 
5,318,221; and 5,326,013. In general, these instruments are provided with 
clamping structure to effect approximation of an anvil and a cartridge to 
secure tissue therebetween, and staple firing structure to effect 
sequential ejection of a plurality of fasteners from the cartridge after 
the tissue has been secured. It would be beneficial however, to provide an 
endoscopic stapling device having actuation structure configured to effect 
progressive approximation of an anvil and a cartridge concomitant with the 
sequential ejection of a plurality of fasteners from the cartridge. 
SUMMARY 
A surgical apparatus for effecting the sequential application of a 
plurality of surgical fasteners to body tissue is provided. The apparatus 
includes a handle portion, a body portion extending from the handle 
portion, a cartridge housing supported at a distal end portion of the body 
portion and containing a plurality of surgical fasteners and defining a 
tissue contacting surface, and an anvil member defining a fastener forming 
surface against which fasteners ejected from the cartridge assembly are 
driven. 
The anvil member is mounted at a location spaced from the handle portion 
and is movable between a first position wherein the fastener forming 
surface is spaced from the tissue contacting surface and a closed position 
wherein the fastener forming surface and the tissue contacting surface are 
in closer cooperative alignment. The apparatus further includes an 
actuator which is configured to progressively move the anvil member from 
the open position to the closed position and concomitantly eject a 
plurality of surgical fasteners from the cartridge to be formed against 
the anvil. A drive mechanism is provided to drive the actuator. The drive 
mechanism is operable from the handle portion and extends through the body 
portion to the anvil member. 
In a preferred embodiment of the surgical apparatus, the cartridge housing 
and the anvil member each have a corresponding longitudinally extending 
slot formed therein for accommodating the translation of the actuator. The 
actuator preferably includes an upper cam beam, a transverse central 
portion, and a lower support beam parallel to the upper cam beam. A 
plurality of spaced apart cam plates are provided on the actuator and are 
configured to engage a plurality of staple pushers disposed within the 
cartridge housing to effect the ejection of surgical fasteners therefrom. 
In one embodiment, a cutting blade is mounted on the actuator for incising 
stapled tissue as the actuator translates through the fastener applying 
assembly. The cutting blade is preferably formed on a leading edge of the 
central portion of the actuator. 
In one embodiment, the drive mechanism includes a pneumatic drive system 
having a canister of compressed fluid disposed within the handle portion, 
a longitudinally extending piston chamber defined in the handle portion, a 
piston configured to translate through the piston chamber, and a drive 
shaft extending from the piston to the actuator. A trigger mechanism is 
preferably associated with the pneumatic drive system to effect a 
discharge of fluid from the canister into the piston chamber to drive the 
piston through the chamber. In an alternative embodiment, a manual drive 
system can be provided which includes a pivoting actuation handle 
associated with said handle portion and operatively connected to an 
elongated drive shaft which extends to the actuator. 
Further features of the surgical apparatus will become more readily 
apparent to those skilled in the an from the following detailed 
description taken in conjunction with the drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
In the drawings and in the description which follows, the term "proximal", 
as is traditional, will refer to the end of the apparatus which is closest 
to the operator, while the term "distal" will refer to the end of the 
apparatus which is furthest from the operator. 
The present apparatus shall be discussed in terms of both endoscopic 
procedures and apparatus. However, use herein of terms such as 
"endoscopic", "endoscopically", and "endoscopic portion", among others, 
should not be construed to limit the apparatus for use only in conjunction 
with an endoscopic tube. To the contrary, it is believed that the 
apparatus may find use in procedures wherein access is limited to a small 
incision including but not limited to arthroscopic and/or laparoscopic 
procedures. 
Referring now to the drawings wherein like reference numerals identify 
similar structural elements, there is illustrated in FIG. 1 a surgical 
stapler constructed in accordance with a preferred embodiment and 
designated generally by reference numeral 10. In brief, surgical stapler 
10 includes a handle portion 12, an elongate tubular body portion 14 
extending distally from handle portion 12, and a fastener applying 
assembly 16 operatively associated with a distal end of body portion 14. 
Fastener applying assembly 16 includes a staple cartridge 18 housing a 
plurality of surgical fasteners and an anvil member 20 pivotably 
associated with the staple cartridge and defining a forming surface 
against which staples are driven when ejected from cartridge 18. As best 
seen in FIG. 1, a rotation control knob 22 is provided at the proximal end 
of body portion 14 and is mounted in such a manner so as to facilitate 
rotation of body portion 14 and fastener applying assembly 16 about a 
longitudinal axis defined by the body portion 14. As illustrated in FIG. 
1A, during an endoscopic procedure, the body portion 14 of surgical 
apparatus 10 is extended through a trocar 15 into the abdominal cavity of 
a patient. Thereupon, tissue is captured between cartridge 18 and anvil 
20, and staples are applied to the tissue. The operation of surgical 
apparatus 10 will be discussed in detail hereinbelow. 
Referring to FIG. 2, staple cartridge 18 is supported within an elongated 
cartridge housing 24 having opposed side walls 26 and 28 and a floor 30. 
As best seen in FIG. 3, cartridge housing 24 is supported in the distal 
end of body portion 14. Notches 26a and 28a are formed in side walls 26 
and 28 respectively, for pivotably supporting a pair of corresponding 
winglets 36 and 38 which extend outwardly from anvil member 20. As shown 
in FIGS. 2 and 4, springs 40 and 42 are associated with anvil member 20 to 
bias the anvil into an open position with respect to cartridge 18. In an 
alternate embodiment, anvil member 20 can be directly attached to the body 
portion 14. In either embodiment, anvil member 20 is positioned distally 
of handle portion, and the fastener firing assembly is remotely actuated 
by the handle portion. 
Alternately, a spring could be provided to bias the anvil to a closed 
position. The spring could extend, for example, from the proximal portion 
of anvil member 20 and be connected to body portion 14 or housing 24. Body 
tissue, when inserted between the anvil and cartridge would move the anvil 
away from the cartridge 18. The anvil would then be loosely clamped on the 
tissue until the actuation mechanism described below is actuated to more 
firmly and progressively clamp the tissue as the fasteners are fired. 
Referring to FIGS. 2 and 3, an actuation mechanism 50 is associated with 
fastener applying assembly 16 to effectuate the progressive approximation 
of anvil 20 and cartridge 18 to clamp tissue therebetween, and 
concomitantly effect the sequential ejection of a plurality of surgical 
staples 34 from cartridge 18. More particularly, actuation mechanism 50 is 
configured to translate through fastener applying assembly 16, i.e. 
through anvil member 20 and cartridge 18, in a distal direction, to 
gradually cam anvil member 20 into a closed (or fully clamped) position 
and, at the same time, activate a plurality of staple drivers 35 to urge 
staples 34 from cartridge 18. An example of a suitable staple driver is 
disclosed in commonly assigned U.S. Pat. No. 4,978,049, the disclosure of 
which is herein incorporated by reference. 
Actuation mechanism 50 includes an elongated support beam 52 having upper 
and lower cam plates 54 and 56 disposed at the distal end thereof, and a 
mounting block 58 disposed at the proximal end thereof. An elongate slot 
60 is formed in anvil member 20 to accommodate the translation of 
actuation mechanism 50 during a stapling procedure. A corresponding slot 
62 is formed in the floor 30 of cartridge housing 24. In use, when 
actuation mechanism 50 translates through fastener applying assembly 16, 
the upper cam plate 54 engages the upper (outer) surface 20a of anvil 
member 20 to urge it toward cartridge 18, and the lower cam plate 56 
engages the under (outer) surface 30a of floor 30 to balance the 
compressive forces imparted on the anvil by the upper cam plate. As shown, 
the upper and lower cam plates 54, 56 are substantially planar. 
Actuation mechanism 50 further includes staple firing bars 70a-70d 
configured to activate staple drivers 35. The firing bars are engaged to 
mounting block 58 at their respective proximal ends by an engagement hook 
74 which is received in a corresponding engagement slot 76. The distal 
ends of each of the firing bars includes a wedged cam surface 78 which 
engages staple pushers 35 as actuation mechanism 50 translates through 
fastener applying assembly 16. The leading edge of support beam 52 defines 
a cutting blade 80 which is configured to form an incision in the tissue 
located between the parallel rows of staples applied by assembly 16. 
Referring to FIG. 5, a pneumatic drive system 90 is operatively associated 
with handle portion 12 to control the translation of actuation mechanism 
50 through fastener applying assembly 16 during a stapling procedure. In 
particular, drive system 90 serves to effect the longitudinal movement of 
a drive shaft 92 which extends from handle portion 12, through body 
portion 14, to fastener applying assembly 16. The distal end of drive 
shaft 92 includes a bifurcated hook portion 94 configured to engage 
corresponding reception slots 96a and 96b in mounting block 58 (see also, 
FIGS. 2 and 3). 
The proximal end of drive shaft 92 extends from a piston 98. Piston 98 is 
configured to translate through an elongate piston chamber 100 which is 
defined within handle portion 12. Piston chamber 100 is in communication 
with a valve assembly 102 through a flexible conduit 104. Valve assembly 
102 is associated with a cylindrical canister 106 containing a supply of 
relatively low pressure compressed gas. A pivoting trigger 108 is 
associated with handle portion 112 and is configured to interact with 
valve assembly 102 to control the emission of gas from supply canister 106 
into piston chamber 100. The structure and operation of the pneumatic 
system is described in detail in commonly assigned U.S. Pat. No. 
5,312,023, the disclosure of which is herein incorporated by reference. 
In operation, as illustrated in FIG. 5, upon manipulation of trigger 108 in 
the direction indicated by arrow "A", valve assembly 102 causes compressed 
gas to flow from canister 106, through conduit 104, and into piston 
chamber 100. As a result of the expansion of the compressed gas within 
chamber 100, piston 98 is driven in a distal direction, as indicated by 
reference arrow "B". At such a time, drive shaft 92 is urged distally, 
driving actuation mechanism 50 into fastener applying assembly 16. The 
distal translation of actuation mechanism 50 causes cam plate 54 to urge 
anvil member 20 toward cartridge 18 to bring the fastener forming surface 
of anvil member 20 into closer cooperative alignment with the tissue 
contacting surface of cartridge 18, clamping the body tissue 110 disposed 
therebetween. Concomitantly, staple drivers 35 are activated by the wedged 
cam surface 78 on each of the staple firing bars 70a-70d, driving staples 
34 through the captured body tissue 110. In addition, cutting blade 80 
travels behind the staple firing bars to incise the stapled tissue. 
As illustrated in FIG. 6, the expansion of compressed gas within piston 
chamber 100, causes piston 98 and actuation mechanism 50 to translate 
distally until each of the staples are ejected from the cartridge 18. 
Thereafter, a coiled return spring 112 disposed within piston chamber 100 
and compressed by the distal movement of piston 98, biases the piston 
proximally, forcing the drive shaft 92 and actuation mechanism 50 to 
return to their distalmost positions. Thereupon, the spent staple 
cartridge can be removed from cartridge housing 24 and replaced with a 
fully loaded cartridge, and apparatus 10 can be utilized once again. 
Although the subject apparatus has been described with respect to preferred 
embodiments, it will be readily apparent to those having ordinary skill in 
the art to which it appertains that changes and modifications may be made 
thereto without departing from the spirit or scope as defined by the 
appended claims.