130 slides through the purse stringed end of the tissue actuating lever 86 can be returned manually to its inop
section 52 in the proximal direction to pull the anvil erative position to retract the staple driver 62. shaft 104 through the purse stringed tissue into the sup- Next, the stapled tissue between the anvil 102 and the
port tube 66. The chamfered surfaces 126 and 144 (FIG. staple holder 68 is released by rotating the adjusting 33) facilitate the movement of the transition point be- 5 knob 82 counterclockwise to advance the anvil assem
tween the trocar body 130 and the sleeve 105 through bly 100 away from the stapling head assembly 60. The
the purse stringed tissue. As described above, the cir- anvil 102 is moved through the lumen by manipulating
cumferential edge 128 of the sleeve 105 is slightly the stapled tissue in a suitable manner to slip the anvil
smaller in diameter than the circumferential lip 142 on through the stapled lumen. Then, the stapling instruthe trocar body 130 to allow the purse stringed tissue to 10 ment 50 is withdrawn from the patient leaving behind
easily move from the chamfered surface 144 to the tne stapled lumen between the tubular tissue sections 52
chamfered surface 126 as the trocar 73 is retracted. m& 54
When the anvil shaft 104 enters the support tube 66, the Furthermore, as seen in FIGS. 44 and 45, there is
external splines 154 (FIG. 34) on the anvil shaft 104 are described a sealing mechanism which allows the instrureceived and guided between the internal splines 156 15 ment of this invention to be used in an endoscopic pro
(FIG. 30) of the support tube 66 to circumferentially cedure. For purposes of interpreting FIGS. 44 and 45,
align the anvil 102 with the staple holder 68. The annu- ®* numerals will be given like characteristics as those
lar edge 67 of the support tube 66 pushes the purse elements in FIGS. 1-43. As seen in FIG. 44, taken in
stringed tissue over the transition between the trocar 73 conjunction with FIG. 45, there are two necessary and the anvil shaft 104 and over the external splines 154. 20 internal Pomte of sealing in order to prevent the passage
Also, the raised circumferential section 152 is tightly ?f ^ *rou^ theu mechanism. The first sealing point is
received by the support tube 66 to align the anvil 102 located oute.de the circumference of the compression
axially with the staple holder 68. As a result of this elfement 92 but "f ^the ^inference of. *e shaft 70
c .. , j -ir_4.4i.4ir of the instrument. This sealing is accomplished by the circumferential and axial alignment the staple forming 500 as seen in FIGS. 44 and 45. This fluted
grooves 108 (FIG. 40) on the anvil 102 are precisely . eAn . ,, . . .. , . . . . ,.
i- J -.I. !l 4 i 14 « /t?t£ «\ r seal 500 is a rubberized cylindrical mechanism roughly
... Th Id 68 ... 0 4 mcheS long Which COntainS f0Ur fluted serrating 502
PC ° • . j , , which envelop the entire inner circumference of the
When the gap between the anvil 102 and the staple shaft 70 ^ seal ents the flow of ^ ^j
holder 68 is set to produce a desired staple height within 3Q the compression dement 92 of this mechanism. Fur
the operating range of the stapling instrument 50 the ^ there can be laceQ within the serrating 502 of the
safety latch 88 is pivoted clockwise, as viewed in FIG. fluted ^ 500 ... of sealing grease, such as
9, to disengage the staple actuating lever 86. The sta- lithium or silicone greaS6) m order t0 further seal the pling instrument 50 is fired by grasping and pivoting the mechanism about the compression element 92 but withstaple actuating lever 86 clockwise, as viewed in FIG. 35 m the internal diameter of the shaft 70.
10, to move the staple actuating lever 86 to its operative Furthei. ^ seen „, FIGS 44 ^ 45 there is described position. As a result, the actuator fingers 350 on the a ... band seal 600. This seal 600 is better seen in trigger arm 340 drive the firing clip 352 m the distal FIG 45 where it is wrapped about the tension bands direction to advance the compression member 92 longi- 95 96 of the instrument at the head of the stapler. The tudinally along the shaft assembly 70. The compression 40 tension band seal 600 is similarly an elastomeric rubbermember 92 advances the staple driver 62 to move the mechanism which may optionally contain silicone driver fingers 63 distally in the staple receiving slots 65 grease or other sealing grease within its internal structo engage the staples 90. The compression member 92 ture. yhis mechanism 600 encloses the tension bands of transmits the required motion and compressive forces the instrument and is held in place at a pair of notch 602, from the trigger arm 340 to the staple driver 62 to drive 45 wnjch are diametrically opposed notches about the the staples 90 from the staple holder 68 into the tissue entjre seal 600. Notch 602 mates with compression eleand against the anvil 102. As shown in FIG. 6, each ment 92 about the tension bands 95 and 96. Therefore, in staple 90 is formed into a B-shaped configuration to the internal portion of this instrument within shaft 70, staple the tissue sections 52 and 54 together. Also, the there is a nearly complete sealing by the fluted seal 500 circular knife 69 is advanced by the staple driver 62 to 50 and the tension band seal 600. Compressed air is precut the tissue against the backup washer 160. As shown vented from being forced down the internal portion of in FIG. 5, the circular knife 69 splits the backup washer the shaft 70 of the stapler.
160 into two annular sections. In order to complete the sealing of this mechanism,
After the stapling and cutting of the tissue is com- there is provided a shrink wrap 700 as better seen in pleted, the staple actuating lever 86 is biased by the 55 FIG. 44. This shrink wrap 700 fits around the external spring 346 to its inoperative position (FIG. 9). The diameter of shaft 70 and the handle extension. The actuator fingers 350 of the trigger arm 340 pivot coun- shrink wrap 700 may optionally contain silicone or terclockwise, as viewed in FIG. 9, to move the firing lithium grease within its inner circumference, or any clip 352 and the compression member 92 in the proximal other seal which allows the shrink wrap to prevent the direction. As a result, the staple driver 62, which is 60 flow of air around the shaft or at the handle seams of the connected by the locator fingers 230 to the compression mechanism. It has been found that these points of entry member 92, and the circular knife 69 are retracted into may cause leakage within the internal chamber of a the stapling head assembly 60. In case of entrapment of trocar. By having a plastic shrink wrap about the shaft, staples, tissue or other debris between the staple holder this leakage is prevented. The shrink wrap 700 may be 68 and the driver fingers 63, the retraction of the staple 65 a mechanism which extends the entire length of the driver 62 frees the stapling head assembly 60 from the shaft 70. However, at least in a preferred embodiment, tissue before the stapling instrument 50 is withdrawn it has been found that shrink wrap 700 need only be at from the patient. If a high force is required, the staple the base of the shaft toward its proximal end.