The end of the sigmoid is then opened. If there is doubt as to the size of stapler needed, retraction stay sutures are placed and circular stapler (EEA) sizers can be passed into the sigmoid to determine the largest size that fits easily (Figure 5). A circumferential purse string of 00 polypropylene suture is placed (Figure 6). The open end of the sigmoid is gently manipulated over the end of the anvil, and the suture is securely tied (Figure 7). The assistant gently dilates the anus and inserts the curved stapler of appropriate diameter (Figure 9). The surgeon assists from above in the passage of the instrument as the spike advances through the rectum, usually just posterior to the stapled stump (Figure 9).
The adequacy of the previously placed purse-string suture is carefully determined. The completeness of the mucosal closure is rechecked to be certain there is no gap between the shaft of the purse-string closure. Bulky puckering of excess tissue must be avoided, lest failure to compress the tissues adequately will lead to failure of the anastomosis. As the assistant closes the instrument from below (Figure 9), the surgeon from above, prevents fatty tissues from being trapped between the bowel ends. The assistant verifies that the stapler is tightened to the correct thickness for the height of its staples as shown by a color-bar indicator in the handle of the stapler. The trigger is released and the handles squeezed to fire and create the anastomosis.
After firing of the stapler, the manufacturer's routine for releasing the instrument is followed carefully to avoid the possibility of disrupting the line of staples during its removal (Figure 10). Additional interrupted sutures may be placed around the anastomosis, and all raw surfaces in the pelvis are reperitonealized where possible.
Before closure of the abdomen, the “doughnuts” created by the instrument must be carefully inspected for 360 degree continuity (Figure 11). A gap indicates a possible leak which will require additional external interrupted sutures. The integrity of the anastomosis is confirmed by filling the pelvis with sterile saline, and air is injected through a catheter or proctoscope ...