For the initial mobilization of the sigmoid colon, the patient is rotated to the right. The sigmoid colon is grasped with an atraumatic forceps and retracted medially. The peritoneal attachments are then divided using the ultrasonic shears and blunt dissection (figure 3). Care is taken to identify the ureter and avoid ureteral injury. The peritoneal attachment is divided up to the splenic flexure. This is facilitated by the first assistant or surgeon providing counter-traction of the colon. As the dissection nears the splenic flexure, it is best to stay underneath the omentum and develop a plan between the omentum and the splenic flexure (figure 4).Dissection between the omentum and the spleen can lead to splenic injury. The omentum is separated for a variable distance along the transverse colon depending on the amount of colon to be removed and the amount of mobility that will be necessary to complete a tension-free anastomosis. Mobilization of the splenic flexure and the transverse colon may be facilitated by a reverse Trendelenburg position. The proximal rectum is mobilized (figure 5). In figure 5, the orientation of the dissection is rotated so the head is to the reader’s left and the foot to the right. The line of mesenteric incision is shown. The surgeon needs to know the anticipated position of the left and right ureter.
Next, control and division of the mesenteric vessels is accomplished. The mesocolon is incised. The course of the ureter should be reverified at this point. A window is made in the peritoneum near the inferior mesenteric vessels. The mesenteric vessels may be divided with linear vascular staples, individually doubly clipped or with coagulation devices designed for this purpose (figure 6). Figure 6 shows the line of division of the mesentery. Staple application provides the most efficient method, but most costly as well. A medial to lateral dissection may be employed, reserving the mobilization of the lateral attachments and splenic flexure until the mesocolon has been divided. Once the mesentery is divided, the transverse colon is brought into the pelvis ensuring adequate mobility for a tension-free anastomosis. The distal colon/rectum is divided using a transversely placed reticulated linear stapler (figure 7). This results in the distal staple line as shown in the figures labeled B. The proximal colon may be divided intracorporally with an endoscopic stapler or after the bowel is exteriorized with a linear stapler through extension of the midline or left lower quadrant trocar incisions. This results in the proximal staple line A. The umbilical incision is extended inferiorly to permit extraction of the specimen, extracorporeal division of the bowel, and preparation of the proximal colon for the anastomosis. Alternatively a left lower quadrant transverse or a Pfannenstiel incision may be made. Prior to bringing the colon through the abdominal wall, a plastic wound protector is used to prevent contamination of the subcutaneous tissue and skin. The anastomosis between A and B is created using a double-staple technique. The exteriorized proximal colon is cleaned and the staple line removed. Dilators are used to dilate the opening of the proximal colon (A). A purse-string suture is placed in the proximal colotomy (figure 8). The anvil for the circular stapler is placed in the bowel (figure 9). The purse-string suture is tied and the colon returned to the peritoneal cavity. The circular stapler is inserted transanally, and the stapler spike is placed through the distal staple line or posterior to it under direct vision (B). The spike is removed with a laparoscopic forceps and removed. The end of the anvil is then inserted into the circular stapler. The stapler is closed and discharged (figure 10). The stapling device is removed and the donuts are inspected for completeness. An incomplete donut indicates an incomplete suture line that will require oversewing. The abdomen is filled with saline and rigid proctoscopy with air insufflation performed in order to examine the anastomosis and to detect air leakage. If air bubbles are encountered, the anastomosis is oversewn with nonabsorbable 3-0 sutures and the air insufflation repeated to verify anastomotic integrity. The mesenteric defect does not require closure. The abdomen should be visually inspected for bleeding.