The first step after establishing pneumoperitoneum and port placement is to explore the abdomen to rule out any metastatic disease and identify the lesion in the colon. The patient is positioned in steep Trendelenburg with right tilt so that the left side is up, and the small bowel is swept to the right to expose the left colon mesocolon. The superior rectal artery is then identified at the level of the sacral promontory. This is facilitated by retracting and tenting the superior rectal artery to the anterior abdominal wall to trace to its origin and opening the peritoneum from below the sacral promontory to the inferior mesenteric artery (IMA) origin on the aorta. The retroperitoneum is swept posteriorly until the left ureter is identified and protected as shown in Fig. 17.3. The IMA is isolated and ligated (can use clips, energy device, stapler, and vessel loop) as shown in Fig. 17.4. The inferior mesenteric vein (IMV) is then identified by separating the mesentery from the retroperitoneum to the inferior border of the pancreas. The IMV is then isolated and ligated (can use clips, energy device, stapler, and vessel loop) as shown in Fig. 17.5. The sigmoid colon and descending colon are retracted medially to free all the lateral attachments along the white line of Toldt, and the omentum is reflected cephalad to the transverse colon to expose the transverse colon and splenic flexure. In order to mobilize the splenic flexure, the superficial peritoneal plane between the omentum and transverse colon is opened toward the midline to enter the lesser sac, and the splenic flexure is then retracted medially and caudally to divide the peritoneal attachments to the inferior border of the pancreas. The splenocolic ligament is divided. By detaching the mesocolon off the kidney at Gerota’s fascia, the last attachments of the colon can be taken down sharply to achieve complete mobilization of the splenic flexure.

The identification of the proximal and distal points of transection can be performed with the assistance of indocyanine green enhanced fluorescence as shown in Fig. 17.6. An intracorporeal transection of the rectosigmoid junction is performed with the laparoscopic stapler at the confluence of the taenia coli. The specimen can be extracted through an extended off midline lower-quadrant trocar site (such as the 12 mm trocar site) or a suprapubic (Pfannenstiel) incision, a technique that is associated with a lower hernia rate.