Single-port colonic surgery has been well described in fair numbers with varying non-standardized techniques and port location. For left colonic surgery, single-port devices have been utilized at the umbilicus, in a suprapubic position (Pfannenstiel incision), and in the right lower quadrant. In patients undergoing primary splenic flexure resection, the most suitable port locations are in the umbilicus with midline extension of the incision above and below as necessary for extraction. Port placement here will allow easy access to even the apex of the flexure with adequate length while still allowing access to the left lower quadrant for mobilization of the sigmoid colon. Stapling the rectosigmoid perfectly from this location may be challenging from this angle; the editors recommend using a posterior-to-anterior or anterior-to-posterior approach when placing the stapler through this site to facilitate.

More flexibility is permitted with port placement when the splenic flexure is mobilized in preparation for left colon resection accompanied by high or low pelvic anastomosis.

The benefits of utilizing a Pfannenstiel port placement are multiple, as both stapling of the rectosigmoid colon and specimen extraction can be accomplished. Additionally, cosmesis is optimal here and postoperative incisional hernia risk is extremely low. Port placement in the right lower quadrant through a muscle splitting incision is desirable for those patients undergoing low anterior resection, especially those with preoperative chemoradiotherapy where a diverting stoma is advised. Single-port proctectomy can be performed, with equivalent results in the hands of experts; however, this remains demanding. Extraction through any single-port site can prove challenging in patients with a bulky tumor or mesocolon, and/or a thick abdominal wall, but can be facilitated by a wound protector included in many commercially available ports. In our experience, enlarging the fascial opening to facilitate extraction is superior to avoid specimen fracture or mesenteric avulsion. Intracorporeal stapling of the proximal or distal colon will nearly always simplify extraction.

Throughout the last two decades, techniques and improvements in laparoscopic colon surgery have continuously evolved. Multiple approaches to the splenic flexure have been described and evaluated with the nomenclature reflecting where one initiates the dissection. As in open colon surgery, early attempts at laparoscopic colonic surgery were generally performed with a lateral to medial approach. This can be initiated anywhere along the mesosigmoid recess, sigmoid colon or descending colon (Fig. 9.2). The colon is gently retracted medially, an incision made along the lateral peritoneal attachments and the mesocolon mobilized off the retroperitoneum maintaining the integrity of Toldt’s fascia. Caution must be taken to find the appropriate plane laterally and not mobilize too deep, posterior to the kidney. Although the most intuitive approach, the lateral approach is challenging in that it requires the surgeon to continuously look over the colon, the splenic flexure can be difficult to turn especially when high, and the critical retroperitoneal structures are not easily identified until later in the dissection.

The medial approach to left colon mobilization, however, begins along the midline at the root of the mesocolic attachments and is traditionally started with a peritoneal incision over the mesosigmoid colon beneath the trunk of the inferior mesenteric artery and toward the sacral promontory. In our experience, the left mesocolic origin can also be targeted at the ligament of Treitz just below the inferior mesenteric vein, which has been mentioned as the inferior approach. Either location allows easy access to the retroperitoneum, early high ligation of the major colonic vascular pedicles, and prompt identification of the left ureter and gonadal vessels, while keeping the colon suspended by its lateral attachments. The inferior approach has become increasingly common for those proponents of routine splenic flexure mobilization. The constancy of the inferior mesenteric vein as it courses by the ligament of Treitz enables immediate clear identification of the initial point of dissection (Fig. 9.3). Inferior mesenteric vein division at the base of the pancreas permits maximal colonic length. This approach permits division of the base of the transverse mesocolon at its origin along the pancreas, entry into the lesser sac, and division of the splenorenal ligaments posteriorly assuring complete mobilization of the splenic flexure.

Lastly, with the supramesocolic approach the dissection begins with entry into the lesser sac, adjacent to the gastroepiploic arcade, leaving the omentum attached to the colon, or along the colon wall which will leave the omentum on the stomach. Gastropancreatic adhesions when present are lysed to expose the entire retroperitoneum. The omentum is divided toward the splenic flexure and lateral abdominal wall. As the lesser sac is opened, the surgeon can clearly denote the plane of dissection between the gastrocolic ligament and epiploic fat which becomes less distinguishable as you approach the flexure and splenocolic attachments. The pancreas is identified, and the origin of the transverse colon is incised along the inferior edge of pancreas down to Toldt’s fascia. The distal transverse mesocolon and left colon are then slowly swept inferiorly off the retroperitoneum.