A total of six ports are inserted under direct visualization. The camera port (C) is placed halfway between the xiphoid process and symphysis pubis. A 12 mm trocar (R1) is inserted in the midclavicular line (MCL) halfway in between C and the right anterior superior iliac spine (ASIS). This port can be used for ileostomy placement and will be used for the insertion of the stapler, if necessary. A second 8 mm trocar (R2) is inserted as a mirror image of R1. The third 8 mm robotic trocar (R3) is inserted 10–12 cm lateral to R2, usually directly above the left ASIS. The first 5 mm laparoscopic port (L1) is inserted in the MCL about 12 cm superior to R1. The second 5 mm laparoscopic trocar (L2) is inserted halfway between MCL and midline a handbreadth superior to L1 (Fig. 21.2).

The four-arm da Vinci robot is docked using the left hip approach once the mobilization of the sigmoid colon is completed (Fig. 21.1). A 0° robotic camera is inserted in port C. Robotic arm 1 is docked to the R1 port; robotic arms 2 and 3 are docked to R2 and R3 trocar, respectively, in sequence. A monopolar scissors is inserted in R1. Alternatively a hook with monopolar energy source can be useful for dissection. A fenestrated bipolar forceps with bipolar energy source is inserted in R2 for holding, traction, and coagulation of vessels. A fenestrated forceps or a robotic suction irrigator devices inserted in R3 for traction. Grasping of the mesorectum should be avoided with the robotic graspers. The assistant uses the two laparoscopic ports. A laparoscopic grasper is used via the L2 port for retraction and manipulation of the sigmoid colon and rectum, and an irrigation and suction system is used via the L1 port for countertraction.

A total mesorectal excision is begun at the sacral promontory using only monopolar and bipolar cautery. The dissection begins posteriorly while the assistant surgeon retracts the rectum cephalad and anteriorly (Fig. 21.4). The avascular plane is between the presacral fascia and the mesorectum. The dissection is continued laterally around the rectum preserving both hypogastric nerves, which are located anterolaterally. Anteriorly, the rectovesical/rectovaginal fold of the peritoneum is incised to expose Denonvilliers’ fascia or the rectovaginal septum. Maintaining a plane posterior to Denonvilliers’ fascia prevents bleeding from the pampiniform plexus surrounding the seminal vesicles in men. The third arm allows for the retraction of the rectum during posterior dissection, the lateral sidewalls during lateral dissection, and the bladder/vagina during anterior dissection.

The dissection is continued distally, and a wide resection of the levators near their origin is carried out using robotic scissors in order to minimize the possibility of a positive circumferential margin (Fig. 21.5a). Care is taken not to lift the rectum off the levator muscle as in a conventional low anterior resection. Instead, the muscle will be taken widely at its origin along the bony structures of the deep pelvis, and the ischiorectal fat will be dissected en bloc using robotic instruments (Fig. 21.5b). The posterior limit of the rectal dissection can be decided by palpating the position of the coccyx tip via digital rectal examination from below while manipulating a robotic instrument on the coccyx from above.