Patient positioning and operating room setup. (Used with permission of Jeremy Moon)
After the abdomen is prepped and draped, trocars are placed. The choice of sentinel trocar placement technique is dictated by the preference of the surgeon. Several techniques exist such as the Veress needle, the Visiport/Optiview trocar technique, the Hasson and the open cutdown technique, or a hybrid of several techniques. Utilizing the laparoscopic principle of triangulation, most surgeons favor the use of multiple 5 mm trocars placed just lateral to the epigastric vessels bilaterally (Figs. 33.2 and 33.3). This reduces the risk of bleeding from the rectus abdominis and the epigastric vessels while at the same time alleviating the risk of abdominal wall hernias and providing adequate reach to the target area. In addition, a 12 mm trocar is required when using the laparoscopic stapler. The ideal location to place the laparoscopic 12 mm stapler trocar is in the umbilical area as this area can be used for extracorporeal anastomosis creation and specimen extraction. However, in the setting of an intracorporeal anastomosis, the 12 mm trocar can be placed anywhere on the abdomen depending on surgeon preference. The use of the articulating endoscopic stapler is useful as it allows the stapler to be fired from almost any angle. The major advantage of an intracorporeal anastomosis is the extraction site can be placed at the Pfannestiel site.
To ensure adequate exposure of the transverse colon, the operating table is placed in a slight reverse Trendelenburg position at about 10 degrees, and the procedure is begun with a diagnostic exploration of the abdominal cavity to determine the extent of the disease. The liver, peritoneal surface, and primary transverse colon tumor location are carefully inspected. Biopsies of the liver or peritoneal surface are obtained with request for frozen sections made when appropriate. If the patient is found to have stage IV disease with peritoneal implants and hepatic metastatic disease, the surgical plan is modified to reduce mortality and morbidity in the perioperative period. For patient with stage IV disease, a palliative resection with a colostomy or a diverting ostomy without resection may be a better option. However, in the absence of metastatic disease, the oncologic procedure can proceed as planned. The anatomic position of the transverse colon mesentery is verified and the proposed resection margins clearly noted (Fig. 33.4a, b).
Adequate exposure is provided by reflecting the omentum in a cephalad position over the liver (Fig. 33.5). The small bowel is retracted gently into the pelvis. A gauze can be placed in the abdominal cavity to provide exposure with gentle traction on the small bowel caudally, as well as to help with hemostatic control during the operative procedure. The small bowel, stomach, and colon should be grasped with an atraumatic bowel grasper to reduce the risk of undue tension and iatrogenic bowel injury during the procedure. Using an energy device of the surgeon’s preference, the gastrocolic ligament is incised separating the colon from the stomach and entering the lesser sac (Fig. 33.6a, b). The splenic flexure is mobilized by taking down the lateral attachments of the colon along the white line of Toldt. The hepatic flexure is also mobilized with care taken to preserve the gallbladder, duodenum, and kidney from harm. The mesocolic dissection is performed by providing gentle traction on the transverse colon. The middle colic vessel exposure is provided by gentle upward retraction using a long atraumatic grasper providing adequate tension of the vascular base (Figs. 33.5 and 33.7a, b).
It is not necessary to ligate the inferior mesenteric vein (IMV) during the splenic flexure mobilization. This will prevent devascularization and congestion of the left colon. High ligation of the middle colic vessel can be performed between clips, a vascular stapler load or vessel sealing device. After ligation of the middle colic vessels, the specimen can be extracted through a small midline incision at the level of the umbilicus. A suprapubic incision may also be used for extraction which has the added benefit of reduction of abdominal wall hernias and less postoperative pain. This requires adequate mobilization, however, to ensure reach. A wound protector should be used to prevent abdominal wall tumor seeding and to reduce the risk of wound infections. An extracorporeal side-to-side anastomosis can be created using a linear stapler and can be ideally performed via the upper midline incision. The common enterotomy can be closed using a linear stapler or suturing. Reinforcing the anastomosis with another layer of suture can be done based on the preference of the surgeon. Prior to performing the anastomosis, the surgeon may elect to use indocyanine green (ICG) angiography to evaluate the vascularity of the proposed sites for the anastomosis. Obtaining surgical margins of at least 5 cm macroscopically is also crucial to prevent local recurrence at the anastomotic site. Depending on the experience and preference of the surgeon, laparoscopic intracorporeal isoperistaltic colo-colonic anastomosis (Fig. 33.8) can be performed using the appropriate laparoscopic endostapler based on tissue thickness. An important advantage of the intracorporeal anastomosis is that it avoids undue tension on the two bowel limbs and the extraction of the specimen can be performed at the Pfannestiel site.