Surgical apparatus with articulating jaw structure

A surgical apparatus is provided which includes a handle portion and an elongated body portion extending distally from the handle portion and defining a longitudinal axis. A tool assembly is operatively associated with a distal end portion of the body portion and includes a first jaw assembly having a proximal jaw portion and a distal jaw portion and a second jaw assembly having a proximal jaw portion and a distal jaw portion. The distal and proximal jaw portions of each jaw assembly are pivotably connected to one another and are movable between first and second articulated positions. A jaw actuation mechanism is provided including an actuation member and having first and second cooperating actuating legs. Each leg is operatively connected to a respective distal portion of the first and second jaw assemblies to effectuate simultaneous pivotable movement of the distal jaw portions relative to the proximal jaw portions of the tool assembly. A jaw control mechanism operatively connects the handle portion and the tool assembly and is configured to effect movement of the tool assembly between an open position and a closed position.

BACKGROUND 
1. Technical Field 
The subject invention relates to surgical apparatus for performing 
endoscopic and laparoscopic surgical procedures, and more particularly, to 
surgical apparatus having articulable jaw structure. 
2. Description of the Related Art 
Endoscopic surgical procedures, and in particular, laparoscopic procedures 
in which small incisions are formed in a patient's abdominal wall to 
provide access for a trocar or cannula device are well known in the art. 
In such procedures, surgical instruments are introduced into the patient's 
abdominal cavity through the narrow pathway defined by the trocar or 
cannula. 
To date, endoscopic cardiac surgical procedures have been less common since 
the instrumentation that is required to perform tasks such as vascular 
bypass procedures are poorly suited for insertion through a trocar or 
cannula. Moreover, many of the required tools for performing bypass 
surgery, such as, for example, vascular clamps, have irregular jaw 
structures which cannot be extended through the narrow pathway provided by 
the cannula. Specifically, these devices have cooperating jaws which 
depend either angularly or arcuately from the longitudinal axis of the 
instrument, making passage through a cannula virtually impossible. 
Consequently, there exists a need in the art for instruments having jaw 
configurations such as these which may be utilized in endoscopic 
procedures, and more particularly during endoscopic bypass surgery. 
It is desirable therefore, to provide an endoscopic surgical instrument 
having angularly or arcuately configured jaw members adapted for insertion 
through a trocar or cannula device, and more particularly, to provide an 
instrument having articulable jaw structure adapted for insertion through 
a cannula device during endoscopic cardiac procedures. 
SUMMARY 
The subject application is directed to a surgical apparatus which includes 
a handle portion and an elongated body portion extending distally from the 
handle portion and defining a longitudinal axis. A tool assembly is 
operatively associated with a distal end portion of the body portion and 
includes a first jaw assembly having a proximal jaw portion and a distal 
jaw portion and a second jaw assembly having a proximal jaw portion and a 
distal jaw portion. The distal and proximal jaw portion of each jaw 
assembly are pivotably connected to one another and movable between first 
and second positions. A jaw mechanism is provided including a bifurcated 
actuation member having first and second cooperating actuating legs. Each 
leg extends at least partially through a respective one of the proximal 
portion of the first and second jaw assemblies and connects with a 
respective one of the distal jaw portions of the first and second jaw 
assemblies. Upon longitudinal translation of the actuation member, the 
distal jaw portions articulate with respect to the proximal jaw portions. 
A jaw control mechanism operatively connects the handle portion and the 
tool assembly and is configured to effectuate movement of the tool 
assembly between an open position and a closed position. 
These and other features of the subject surgical apparatus will become more 
readily apparent to those skilled in the art from the following detailed 
description of the subject application.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The apparatus disclosed herein will be discussed in terms of endoscopic 
procedures and apparatus. However, use herein of terms such as 
"endoscopic" should not be construed to limit the present application to 
an apparatus for use only in conjunction with an endoscopic tube. In 
addition, it is believed that the present apparatus may find use in 
laparoscopic or arthroscopic surgery wherein access to the surgical site 
is achieved through a narrow cannula or trocar device. 
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 which is 
furthest from the operator. 
Referring now in detail to the drawings in which like reference numerals 
identify similar or identical elements, a preferred embodiment of the 
surgical apparatus of the subject invention is illustrated in FIG. 1, and 
is designated generally by reference numeral 10. Surgical apparatus 10 
includes a handle assembly 12 defining a stationary handle 14, a pivoting 
handle 16, and a barrel portion 18. An elongated endoscopic portion 
extends from the barrel portion 18 of handle assembly 12 and includes 
elongated outer tube 22, and outer housing 24. Tool structure, 
specifically, in this case, vascular clamp 26, is operatively connected to 
a distal portion of endoscopic portion 20 and may be formed in a wide 
variety of configurations including graspers, dissectors, forceps, and 
other types of clamps. 
Vascular clamp 26 includes a pair of cooperating jaw assemblies 28, 30, 
which open and close in a plane designated by directional arrow "A" in 
response to movement of pivoting handle 16 in the direction of arrow "B". 
Left jaw assembly 28 includes proximal jaw portion 32 and distal jaw 
portion 36. Right jaw assembly 30 includes proximal jaw portion 34 and 
distal jaw portion 38. Distal jaw portions 36, 38 are progressively 
articulable with respect to the proximal jaw portions 32, 34, as 
illustrated by arrow "C" in FIG. 1. 
An articulation assembly which includes articulation knob 40 is located at 
a proximal portion of endoscopic portion 20 to effect relative movement of 
the distal jaw portions. Specifically, articulation is effectuated by 
rotation of articulation knob 40 in a direction indicated by arrow "D". 
Rotation of the clamp assembly 26 in the direction of arrow "E" about the 
longitudinal axis defined by endoscopic portion 20 is remotely achieved by 
rotation knob 42 provided at the barrel portion 18 of the handle assembly 
12. The profiles and inner clamping surfaces of jaw assemblies 28, 30 may 
be configured as surgical procedures require. Preferred embodiments of jaw 
assemblies 28, 30 will be described hereinbelow. 
Approximation Mechanism 
Referring to FIG. 2, handle assembly 12 of surgical apparatus 10 includes 
stationary handle 14, which is composed of complementary sections 44, 46. 
A portion of a stepped bore 48 is provided in sections 44 and 46 for 
accommodating various components which will be described hereinbelow. A 
proximal control member 50 is slidably supported within stepped bore 48. 
Proximal control member 50 includes a proximal head portion 52 which is 
retained in a universal joint assembly 54 including retaining clip 
portions 55a, 55b disposed within an aperture 56 formed in the pivoting 
handle 16 of handle assembly 12. Relative movement of pivoting handle 16 
with respect to stationary handle 14 about pivot pin 15 effectuates the 
reciprocal longitudinal displacement of proximal control member 50, 
thereby progressively opening and closing jaw assemblies 28 and 30 
operatively connected thereto, as will be described hereinbelow. 
Surgical instrument 10 further includes an indexing mechanism to control 
movement of pivoting handle 16 with respect to the stationary handle 14. 
This permits incremental closure of jaw assemblies 28 and 30. A return 
spring 198 biases pivoting handle 16 to an open position corresponding to 
a distal position of proximal control member 50 and an open position of 
jaw assemblies 28 and 30 (See, FIG. 7). Proximal control member 50 is 
provided with a ratchet assembly having a rack 84 and a pawl 88. Rack 84 
is composed of annular sloped notches 86 which permit engagement with pawl 
88 independent of the angular orientation of proximal control member 50 
about the longitudinal axis. Pawl 88 is supported on stationary handle 12 
and pivotably interconnected to trigger 92. Pawl 88 is normally biased 
into engagement with rack 84 by ratchet spring 90 disposed within spring 
sleeve 91. Sloped notches 86 permit incremental movement of proximal 
control member 50 in a first longitudinal direction, while inhibiting 
motion in a second, opposite longitudinal direction. Preferably, sloped 
notches 86 are configured to permit proximal motion of control member 50 
while inhibiting distal motion thereof. Consequently, pivoting handle 16 
is inhibited from opening further with respect to stationary handle 14, 
and thus clamp assembly 26 is maintained in a desired position. A trigger 
92 is provided to pivot the pawl 88 against the ratchet spring bias and 
out of engagement with rack 84 to permit opening of pivoting handle 16. By 
maintaining pressure on trigger 92, unrestricted movement of pivoting 
handle 16 and clamp assembly 26 is enabled. 
As illustrated in FIG. 3, proximal control member 50 is slidably connected 
to a distal control member 58. A longitudinal slot 64 extends axially 
through opposite sides of proximal member 50 at a distal portion thereof. 
Slot 64 terminates at distal head portion 62 and is aligned with a 
substantially rectangular aperture 66 extending through distal head 
portion 62 for receiving proximal end portion 68 of distal control member 
58. A substantially rectangular cross-section of distal control member 58 
is sized and configured to be inserted within aperture 66 and reciprocate 
longitudinally within slot 64. A retaining clip 70 is provided with a pair 
of prongs 72 that surround an annular notch 74 at the proximal end portion 
of rectangular portion 68, and fit within longitudinal slot 64, such that 
retaining clip 70 is fixed with respect to distal control member 58 and 
slides therewith in slot 64 (See, FIG. 5). An annular spacer 61 is sized 
to fit around the cooperating proximal control member 50 and rectangular 
portion 68 of distal control member 58, and is restrained from proximal 
movement by a bearing surface 78 of retaining clip 70. 
Referring now to FIG. 4, a biasing member, such as drive spring 60, 
maintains proximal control member 50 in alignment with distal control 
member 58. Preferably, drive spring 60 is a conventional stainless steel 
helical spring with a distal end portion abutting an annular bearing 
surface on distal head portion 62 and a proximal end portion abutting the 
annular spacer 61. The spring characteristics of drive spring 60 are 
selected such that a fixed relative displacement of control members 50, 58 
is generally provided. However, drive spring 60 permits some differential 
displacement of distal control member 58 with respect to proximal control 
member 50 upon encountering substantial resistance. This resilience 
permits the jaw assemblies 28, 30 to yield slightly when adjusted by 
pivoting handle 16 against a resistant structure. Alternatively, it is 
envisioned that jaw assemblies 28 and 30 can be actuated by a single 
control member replacing proximal control member 50 and distal control 
member 58. 
Referring now to FIG. 6, the distal portion of surgical apparatus 10 will 
be described. As noted above, each jaw assembly includes a proximal and 
distal jaw portion. Proximal jaw portions 32 and 34 each include a flange 
portion 120a and 120b for pivotably mounting to outer tube 22, an 
intermediate portion 122a and 122b, and a clevis portion 124a and 124b for 
respectively connecting to distal jaw portions 36 and 38. Flange portions 
120a and 120b are provided with an angularly disposed cam slot 126a and 
126b and an adjacent pivot aperture 128a and 128b. Proximal jaw portions 
32 and 34 each pivot about pivot pin 132 which is mounted at a distal end 
of outer tube 22. Cam slot 126a in jaw section 32 is disposed at an angle 
complementary to the angle at which the cam slot 126b in proximal jaw 
portion 34 is disposed. A cam pin 130 is mounted at the distal end of 
distal control member 58 and is positioned to translate within cam slots 
126a and 126b. Cooperative movement of proximal jaw portions 32 and 34 is 
effectuated between an open position and a closed position in response to 
reciprocal longitudinal movement of distal control member 58. 
Turning to FIGS. 7--8, approximation of jaw assemblies 28 and 30 is 
achieved by movement of pivoting handle 16 with respect to stationary 
handle 14. Referring particularly to FIG. 7, the open position of jaw 
assemblies 28, 30 corresponds to proximal control member 50 and distal 
control member 58 both being disposed in a distal position. In addition, 
return spring 198 is disposed between stationary handle 14 and pivoting 
handle 16 and guided by plunger 199 passing through the center of return 
spring 198 to maintain distal control member 58 in the distal position by 
normally biasing pivoting handle 16 in a position spaced from stationary 
handle 14, and pawl 88 is normally engaged with sloped notch 86 of rack 84 
to inhibit distal movement of control member 50. It is also contemplated 
that in the distal position, with the jaws open, the pawl need not be 
engaged with the rack. 
As illustrated in FIG. 8, in operation, progressive approximation of 
pivoting handle 16 with respect to stationary handle 14 in the direction 
of arrow "B" against biasing spring 198 translates such pivotal movement 
to longitudinal proximal movement of control members 50, 58 as indicated 
by arrow "L". Proximal movement of control member 58 and camming pin 130, 
which is movable therewith, approximates jaw assemblies 28 and 30 by 
camming interaction with camming slots 126a, 126b as described above. 
Articulation Mechanism 
Referring to FIG. 4, there is shown preferred mechanism for effectuating 
the articulation of distal jaw sections 36 and 38 relative to proximal jaw 
portions 32 and 34. The mechanism includes articulation rotating knob 40 
which has a fluted outer surface to facilitate gripping by the user. The 
knob is provided with a stepped bore 94 having internal threading 96 on a 
portion thereof for engagement with corresponding threading on 
articulation screw 102. Knob 40 is mounted for rotational movement and is 
restrained against longitudinal movement by outer housing 24 at a proximal 
portion and at a distal portion by retainer 98 and shim 100. Shim 100 can 
be precisely machined at the time of assembly of the surgical apparatus 10 
to insure a close tolerance with the distal portion of knob 40. 
External threaded portion 104 on an outer surface of articulation screw 102 
(FIG. 9) is configured to engage internal threading 96 of articulation 
knob 40 in order to transfer rotational motion of knob 40 to longitudinal 
displacement of articulation screw 102. Articulation screw 102 has a 
longitudinal bore and is dimensioned to be concentrically slidable over 
distal control member 58. FIG. 4 illustrates the location of a pair of 
stop plates 106a, 106b provided at the end portions of articulation screw 
102. Stop plates 106a, 106b restrict the longitudinal displacement of 
articulation screw 102, and consequently the articulation of distal jaw 
portions 36, 38. In the preferred embodiment, both stop plates 106a, 106b 
and the proximal and distal faces 95, 97 of the internal treaded portion 
96 are provided with a plurality of radially aligned, longitudinally 
extending projections 108 which intermesh when screw 102 reaches the 
preset limits of longitudinal displacement, thereby preventing further 
rotation of knob 40. FIG. 4 illustrates articulation screw 102 at its 
distal limit of travel, wherein proximal face 97 of knob 40 abuts stop 
plate 106b. The distal portion of articulation screw 102 is connected to 
10 articulation tube 110 and bushing 174 which, in turn, are operatively 
connected with assemblies 28, 30. 
In the portion of the description which follows, articulation will be 
described with regard to right jaw assembly 28, including distal jaw 
portion 36 and proximal jaw portion 32 only, although the mounting and 
articulation of left jaw assembly 30 occurs simultaneously in a 
substantially identical manner. 
With initial reference to FIG. 6, proximal jaw portion 32 includes a clevis 
portion 124 having spaced apart shackles 134a, 134b defining a recess 137 
for receiving the mounting portion 158 of distal jaw portion 36. Apertures 
142a, 142b extend through shackles 134a, 134b. Mounting portion 158 of 
distal jaw portion 36 is provided with a first aperture 162 which 
corresponds with apertures 142a, 142b in shackles 134a, 134b of proximal 
jaw portion 32 for receiving barrel pin 146a. Articulation of distal jaw 
portion 36 with respect to proximal jaw portion 32 occurs about barrel pin 
146a (See, FIG. 14). 
With continued reference to FIG. 6, articulation of jaw assembly 28 occurs 
by movement of an actuation mechanism including cylindrical bushing 174, 
articulation wire 180, and actuating legs or linkage members 154, 156. As 
illustrated in FIG. 17, recess 137 in proximal jaw portion 32 between 
shackles 134a, 134b is configured to receive mounting portion 158 
including elongated linkage aperture 164 and a distal portion of a linkage 
member 154, which are pivotably linked by linkage pin 152a. A linkage 
aperture 164 in mounting portion 158 is offset from pivot aperture 162 
such that longitudinal movement of linkage member 154 effects articulation 
of distal jaw portion 36. Elongated slots 148a, 148b extending through 
shackles 134a, 134b are configured to slidably receive linkage pin 152a to 
provide additional stability to the articulation mechanism. Linkage member 
156 is similarly linked to distal jaw portion 30 by linkage pin 152b. 
Referring back to FIG. 6, cylindrical bushing 174 is connected at the 
distal end of articulation tube 110 and is concentric with and surrounds 
distal control member 58 and is slidable within outer tube 22. 
Alternatively, the articulation screw 102, tube 110, and bushing 174 may 
be machined or formed in a single, integral piece. Bushing 174 transfers 
longitudinal movement of articulation screw 102 to the distal portion of 
the apparatus 10. Articulation wire 180 is connected to bushing 174 at one 
end and to respective linkage members 154 and 156 at the other end in 
order to effectuate the previously described longitudinal movement of 
linkage members 154 and 156. 
FIGS. 14-15 illustrate the progressive articulation of distal jaw portion 
36 with respect to proximal jaw portion 32 about pivot pin 146a. FIG. 14 
illustrates linkage member 154 disposed in a proximal position adjacent 
proximal jaw portion 32. This corresponds to a non-articulated position of 
distal jaw portion 36. Referring now to FIG. 15, linkage member 154 has 
moved in a distal longitudinal direction as indicated by arrow "L", 
thereby pivoting distal jaw portion 36 in the direction of arrow "C". 
Linkage pin 152a travels longitudinally in slots 148a, 148b to stabilize 
and direct the movement of linkage member 154 within recess 137. (See, 
FIG. 17) 
Turning to FIG. 18, articulation wire 180 is configured to be formed of 
stainless steel spring wire or a resilient shape memory alloy, the 
configuration of which can be controlled by applying a mechanical stress 
to the material. Consequently, linear sections 184a, 184b of articulation 
wire 180 are capable of bending as indicated in phantom. The connection of 
linkage members 154, 156 to proximal jaw portions 32, 34 by means of 
linkage pins 152a, 152b enables linkage members 154, 156 to move with 
proximal jaw sections 32, 34 as indicated by arrow "P" from a closed 
position indicated in solid line to an open position indicated in phantom. 
Linkage member 154 is provided with flange portion 190 having a pin 192 
that cooperates with a channel 196 in flange portion 194 in linkage member 
156. Pin 192 is slidable within channel 196 when proximal jaw sections are 
in a partially closed to fully closed position to prevent undesired 
asymmetrical articulation of one distal jaw portion with respect to the 
opposite side distal portion. 
Rotation Mechanism 
With reference to FIG. 2, surgical apparatus 10 includes a mechanism for 
rotating endoscopic portion 20 about its longitudinal axis relative to 
stationary handle portion 14 to increase the range of operability of the 
instrument. The elongated endoscopic portion 20 including outer housing 24 
is rotatably mounted within the stepped bore 48 of barrel portion 18. 
Rotation knob 42 includes pin 41 disposed within notch 43 at the proximal 
end of outer housing 24 and operatively connects knob 42 to housing 24 so 
that upon rotation of knob 42, jaw assemblies 28 and 30 are rotatable 
therewith about the longitudinal axis. Handle sections 44, 46 are each 
provided with a longitudinally extending projection 112 and 114, 
respectively, engagable with a radial gearing (not shown) provided on a 
proximal face of rotation knob 42. Compression spring 118 biases the 
gearing of rotation knob 42 into engagement with projections 112 and 114 
to facilitate indexed rotation of endoscopic portion 20 and jaw assemblies 
28 and 30 in radially indexed movements. 
Jaw Configuration 
Referring now to FIGS. 19-22, there is shown one embodiment of the subject 
jaw assembly which takes on the form of a conventional Fogarty clamp in a 
fully deployed orientation. The distal jaw portion 238 includes a body 
portion 260 having a generally elongated configuration with a partially 
curved portion 240 adjacent the mounting portion 258 thereof. Two rows of 
interdigitating teeth 270 and 272 are formed along the length of distal 
jaw portion 238, with one row being disposed adjacent each peripheral edge 
of the jaw. As best seen in FIG. 20, channel 274 extends between rows 270 
and 272 along a medial portion of the jaw to receive tissue gripped by the 
rows of teeth. The curvature of the jaw enables the surgeon to reach and 
clamp blood vessels and other structures without interfering with 
neighboring tissue. As indicated in FIG. 22, two rows of interdigitating 
teeth 276 and 278 can be formed on proximal jaw portion 232 extending from 
clevis portion 224 to intermediate portion 222. Channel 280 extends 
therebetween, and is interrupted at aperture 242a. When proximal jaw 
portion 232 and distal jaw portion 238 are pivotably linked by a barrel 
pin 146a (See, FIG. 6) inserted through apertures 262a and 242a, the rows 
of interdigitating teeth 270, 272, and 276, 278 form a continuous contact 
surface extending along the distal portion 238 and proximal portion 232. 
Referring to FIG. 20, the cooperating distal jaw sections 236 and 238 are 
substantially identical, although mirror images of one another. Thus, the 
rows of interdigitating teeth on each jaw engage one another and a cavity 
is formed by the interposition of channel 274 for the reception of tissue 
gripped by teeth 270, 272 and 276, 278. 
Turning now to FIGS. 23--26, there is shown another embodiment of the 
subject jaw assembly which takes the form of an Aortic Clamp in a fully 
deployed orientation. FIG. 23 illustrates distal jaw section 338 having a 
body portion 360 with a substantially constant radius of curvature "r". 
Two rows of interdigitating teeth 370 and 372 are provided on the edges 
along the length of distal jaw section 338. Distal jaw portion 338 
cooperates with distal jaw portion 336. As depicted in FIG. 24-A, distal 
jaw portion 338 includes a recess or channel 374 extending along a 
substantial length of body portion 360. Between the two rows of 
interdigitating teeth 376 and 378 of distal jaw portion 336 is disposed a 
rib or projection 376 which extends along a substantial length of body 
portion 361 of distal jaw portion 336 and engages channel 374 of distal 
jaw section 338. The interaction of rib 376 within channel 374 compresses 
tissue structure such as blood vessels gripped between distal jaw sections 
336 and 338. Transverse compression across a blood vessel would be useful 
to inhibit blood flow therethrough. FIG. 26 illustrates proximal jaw 
portion 332 having two rows of teeth 376 and 378 extending from the 
intermediate portion 322 to the clevis portion 324 and a channel 380 
extending therebetween. Cooperating proximal jaw section (not shown) 
includes a channel to receive the rib or projection between the two rows 
of interdigitating teeth for interacting with channel 380 in proximal jaw 
section 332 to effectuate compression of vessels gripped therebetween. 
Clearly, the rib or projection can be formed on this proximal jaw section 
with the channel formed in the other proximal jaw section. 
FIGS. 27-30 illustrate yet another embodiment of the present jaw assembly 
which takes the form of an Aortic Occlusion Clamp in the fully deployed 
position. FIG. 27 illustrates distal jaw portion 438 having body portion 
460 with a non-linear configuration. Body portion 460 includes a proximal 
linear portion, a radiused intermediate portion and a distal linear 
portion. Extending along the length of body portion 460, in a medial 
portion, is a contact surface consisting of three adjacent rows of 
interdigitating teeth 472 having a staggered configuration. As illustrated 
in FIGS. 28-A and 28-B, teeth 472 of distal jaw portion 438 cooperate with 
teeth 474 of distal jaw portion 436 in order to grip and occlude vessels 
gripped therebetween. Referring to FIG. 30, clevis portion 424 and 
intermediate portion 422 of proximal jaw portion 432 are also provided 
with three rows of interdigitating teeth to provide a continuous contact 
surface across the proximal and distal jaw portions. 
Operation of the Surgical Apparatus 
In use, surgical apparatus 10 is normally prepared for insertion into the 
body cavity by placing jaw assemblies 28 and 30 in a closed position 
corresponding to pivoting handle 16 being in approximation with stationary 
handle 14 (See FIG. 8). Articulation knob 40 is rotated to position jaw 
assemblies 28 and 30 in a non-articulated or substantially straight 
configuration (See, FIGS. 1 and 14). Surgical apparatus 10 can be inserted 
in the body cavity either through a cannula or a small incision. 
Once inside the body cavity, jaw assemblies 28 and 30 may be remotely 
manipulated at handle assembly 12 as surgical conditions require. In 
particular, trigger 92 is depressed to disengage pawl 88 from engagement 
with rack 84. By maintaining pressure on trigger 92, pivoting handle 16 
may be opened, thereby camming jaw assemblies 28 and 30 to an opened 
position. Turning rotation knob 42 in incremental movements is performed 
to rotate jaw assemblies to the desired angular orientation near a blood 
vessel or tissue structure. Progressive articulation of jaw assemblies 28 
and 30 to their deployed configuration (See, FIG. 15) is effectuated by 
rotation of articulation knob 40. Subsequent to positioning of jaw 
assemblies 28 and 30 about the tissue to be grasped, closure of the jaws 
is achieved by approximating the pivoting handle 16 with the stationary 
handle 14. The user will detect either audibly or in a tactile sense the 
progressive engagement of pawl 88 with rack 84. If closing force is 
removed from the handle portion, i.e. the surgeon releases handle assembly 
12, then rack 84 and pawl 88 acting in conjunction with return spring 198 
will maintain the selected closure of the jaw assemblies. The foregoing 
sequence of opening the jaw assembly, rotation, articulation and closure 
is described as illustrative only, since such functions of apparatus 10 
may be performed in any order that surgical conditions may require. 
Removal of surgical apparatus 10 from the operative site is normally 
achieved by closing jaw assemblies 28 and 30 and returning them to the 
non-articulated or straightened configuration. 
It will be understood that various modifications may be made to the 
embodiments disclosed herein. For example, the jaw assemblies may be 
provided with different profiles and tooth configurations. Therefore, the 
above description should not be construed as limiting, but merely as 
exemplifications of preferred embodiments. Those skilled in the art will 
envision other modifications within the scope and spirit of the claims 
appended hereto.