Place the patient in a modified lithotomy position with the hips and knees gently flexed at a maximum 15-degree angle. Greater elevation of the thighs may not allow the surgeon to freely move the instruments. The buttocks should slightly extend over the end of the operating table. This position gives proper access to the anus for endoscopy and for insertion of a circular anastomotic device and also allows access to the perineal region for abdominoperineal resection. Both arms are tucked at the patient’s side and must be carefully padded to help avoid ulnar or brachial plexus injury. The patient must be safely secured to the bed by either taping, use of beanbag, or shoulder restraints. A monitor is placed on each side of the patient. Bilateral ureteral stents are placed by a urologist at the discretion of the surgeon. A warm-air, upper-body warmer across the chest and above the nipple line is used to help avoid hypothermia. Place an orogastric tube and a urinary catheter to minimize the risk for gastric or bladder injury, respectively, during trocar insertion. Prepare and drape the abdomen and perineal region for a laparotomy in case a laparoscopic procedure cannot be completed. The surgeon stands on the right side of the patient, the first assistant surgeon on the left, and the second assistant, who controls the camera, to the left of the surgeon.

A CO₂ pneumoperitoneum of 12 to 15 mm Hg is established in the usual fashion, through a small vertical infraumbilical incision. A 30-degree laparoscope is then introduced, and the abdomen is thoroughly explored to assess other pathology and to determine any metastatic dissemination. To inspect the liver, the patient is brought into a steep reverse Trendelenburg position; if desired, a laparoscopic ultrasound of the liver may be performed.

If the proposed operation is deemed feasible, the other ports will be positioned. The operation is facilitated by the camera and the instruments being interchangeable to all ports. The 10-mm bipolar energy device is preferred for division of the inferior mesenteric artery and vein. Accordingly, only 10- to 12-mm trocars are used; three operating port sites are usually sufficient. Place the additional trocars under direct laparoscopic visualization in the right lower quadrant and in the right upper quadrant in the midclavicular line. The port positioning takes into account the patient’s anatomy, the location of the incision for specimen retrieval, and the site of any planned stoma. An optional fourth 10-mm port may be placed in the left lower quadrant to help mobilize the splenic flexure in tall patients, retract the small bowel in obese patients, and retract the uterus in women with a large uterus. This optional port may also be useful for retraction of the prostate and seminal vesicles in men with a narrow pelvis.

The following additional instruments are required.

Place the patient in a steep Trendelenburg position with the table tilted to the right side so that the small bowel gravitates toward the right upper quadrant of the abdomen and no retraction to the small bowel is required. Gently grasp the sigmoid colon
with a Babcock clamp or atraumatic bowel grasper through the right paraumbilical port, and move the bowel to the patient’s right side. This maneuver places traction on the posterior peritoneum overlying the iliac vessels. Incise the peritoneum with the ultrasonic scalpel, harmonic scalpel, or shears with cautery placed through the right lower quadrant port. Sequentially slide the device under the peritoneum, and advance it down the pelvic sidewall toward the anterior peritoneal reflection, using it to push the mesorectum and mesosigmoid medially away from retroperitoneal structures. Identify the ureter as it crosses the iliac vessels and trace it proximally as far as possible.

The abdominal and pelvic part of the ureter lies in extraperitoneal areolar tissue. The abdominal part, which descends on the medial part of the psoas major muscle, enters the lesser pelvis anterior to the end of the common iliac vessels or the beginning of the external iliac vessels. The left ureter lies beneath the root of the sigmoid mesocolon. The right ureter lies behind the lower part of the mesentery and the terminal ileum. In the pelvis, the ureter is anterior to the internal iliac artery and is covered by the parietal endopelvic fascia. Laterally, it lies on the fascia of the musculus obturator internus. In males, the ureters pass between the internal iliac vessels and the ascending vas deferens. Then they turn anteriorly, pass along the levator ani, and penetrate the base of the bladder in front of the seminal vesicles. In females, the pelvic part at first has the same relations as in males, but anterior to the ureters lie the ovaries. At the pelvic floor, the ureter turns anteriorly on the levator ani, turns forward slightly above the lateral vaginal fornix, and then inclines medially to reach the bladder.

Place the patient in a steep reverse Trendelenburg position. This position allows the transverse colon and viscera to fall away from the spleen and the stomach. While the assistant retracts
the splenic flexure toward the umbilicus with the Babcock clamp, separate the mesentery of the descending colon from Gerota fascia until the splenic flexure is reached.