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 in the rectum. The appearance of air bubbles identifies the presence of a leak that must be repaired by interrupted sutures. If there is any doubt concerning the security of the final anastomosis, a temporary proximal diverting loop ileostomy (Plate 58) should be considered. As the assistant tightens the clamp from below, 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 pressed to fire the instrument, and the bowel wall is anastomosed.
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. Additional interrupted sutures may be placed around the anastomosis. All raw surfaces in the pelvis are retroperitonealized where possible.
Before closure of the abdomen, the “doughnuts” removed by the instrument must be carefully inspected for any evidence of a possible defect, which will require additional interrupted sutures. After filling the pelvis with sterile saline, air may be injected through a catheter or proctoscope is passed into the rectum. The presence of air bubbles confirms the presence of a leak that must be repaired by interrupted sutures. When there is any doubt concerning the security of the final anastomosis, a temporary proximal diverting loop ileostomy (Plate 58) should be considered.
Most surgeons prefer temporary drainage of the presacral space with closed suction silastic drains. The drains are left in place for a few days until the fluid becomes more serous and smaller in volume. If large volumes of rather clear fluid are noted, then a urea content should be checked and the bladder and ureters evaluated.
A point on the sigmoid is selected for division, and the mesenteric border is meticulously cleared for a distance of approximately 2 cm. Active pulsations must be present in the mesentery. The cleared area must be free of diverticuli. The purse-string clamp is applied obliquely to the bowel so as to preserve the 2-cm cleared bowel proximally. This is necessary as the 2-cm zone will be enclosed within the stapler anvil and will become the upper “doughnut.” If the wall is not carefully cleaned of fat, or if too thick a turn-in is created with a purse-string suture that is placed freehand, the entire circumference of the bowel may not be brought inside the instrument. This will result in an incompetent anastomosis and leak. Accordingly the placement of the purse-string sutures and the examination of the upper and lower “doughnut” rings for intact purse-string sutures with 360 degrees of full-thickness bowel wall turn-in are most important steps with these instruments. A 00 polypropylene suture on a long, straight Keith needle is passed through the special openings in the purse-string clamp, and a purse-string suture results. A straight Kocher clamp is applied on the colon distal to the purse-string clamp and the bowel is divided in between. The rectosigmoid is retracted forward toward the symphysis as the peritoneum is incised and the rectal segment mobilized from the presacral space using mesorectal dissection (Plate 70). The posterior rectal wall is cleared of fat until at least 2 cm of only the bowel wall is exposed approximately 5 cm or more distal to the tumor. In the male and very obese patient, it is difficult to properly place the purse-string clamp and even more difficult to insert the Keith needle to complete the purse-string anastomosis. Under such circumstances, a noncrushing vascular clamp is placed across the area cleared for the anastomosis similar to that shown in Plate 80, Figures 4 & 5. A Kocher clamp secures the proximal specimen and the bowel is divided. The end of the sigmoid should be brought down to the divided end of the rectum to verify once again the adequacy of mobilization in order to avoid any chance of tension on the suture line of staples. Additional mobility may be gained by ligating and dividing the inferior mesenteric vein just below the inferior margin of the pancreas. The decision now must be made whether to perform an open sutures anastomosis as shown in Figures 8 & 9 on Plate 80 or to use the transrectal circular stapler after placing the rectal stump purse-string suture by hand in a very low anastomosis. In these cases some surgeons prefer to place the purse-string suture in the very short rectal stump from below using an anal speculum. More frequently, it is technically easier to maintain compression of the rectal wall with a right angle vascular clamp while a purse-string suture is placed in the protruding mucosa. Absorbable traction sutures can be placed to serve as stay sutures, while the purse-string suture of 00 polypropylene sutures includes both in the muscular and mucosal layers. Also this suture must be placed closeto the cut edge so as to ensure a snug approximation of the entire bowel wall about the stapling instrument when it is tied. Blunt EEA sizing instruments are passed into the open proximal bowel lumen and into the rectum to define the largest-diameter stapler possible. The assistant gently dilates the anus and inserts the circular EEA stapler from below. The remainder of the procedure is same as described in METHOD 1.
Routine procedures are followed.
Some postoperative rectal bleeding may occur but usually stops spontaneously. The diet is slowly resumed after the patient passes flatus. Some prefer to insert a catheter in the anus beyond the anastomosis for the venting of gas and anchor the catheter with a silk suture to the perianal skin. The Foley catheter is removed after 5 days with careful observation of the volume and patterns of voiding. The patients may complain of increased frequency and urgency that may persist for several months. A tight anastomosis may require eventual gentle dilations.