All patients receive a preoperative full mechanical bowel preparation. Perioperative antibiotics are administered for 24 hours.

In anticipation of surgery in the deep pelvic space, the surgeon must ensure optimum visualization of tissue planes. In order to achieve this, preoperative procurement of adequate assistance, retraction, and illumination is important. Deep pelvic retractors, such as the St Mark’s retractors, are important for adequate exposure. For patients with a narrow pelvis, the illuminated, narrow blade St Mark’s retractors are especially helpful. The use of a headlight can also facilitate adequate visualization in the deep pelvis.

As was demonstrated by Pokala et al. (5), selective use of ureteral stents for adequate localization of the ureters can also be beneficial.

The patient is placed in the modified lithotomy position with careful attention to adequate padding to avoid injury to the peroneal nerve that may result in postoperative foot drop.

The surgery is approached via a midline incision. Upon entering the abdomen, a thorough exploration is performed to exclude metastatic disease. The sigmoid and descending colon are mobilized medially and the left ureter is identified. An assessment is made about the length of the descending and sigmoid colon, and the need for splenic flexure mobilization. Brennan et al. (6) reported on their experience with selective mobilization of the splenic flexure during anterior resection for rectal cancer. The ability to create a tension free and well-vascularized anastomosis determines the need for splenic flexure mobilization. The splenic flexure mobilization is facilitated with the operating surgeon standing between the legs of the patient in the modified lithotomy position. A recent study from Cleveland Clinic Florida evaluated patients referred for redo colorectal anastomosis for anastomotic stricture. In virtually every instance the splenic flexure had not been mobilized and neither the inferior mesenteric artery nor vein had been proximally divided (CCF Ref).

The peritoneum on both sides of the rectum is incised at the level of the sacral promontory, with care to avoid injury to the ureters and to the sympathetic nerves. Various means of identification of the nerves have been dissected but are rarely needed (Silva et al.). The dissection is carried underneath the superior rectal artery, and the superior rectal artery is dissected to the level of the left colic artery and inferior
mesenteric artery. The decision of the location of vessel ligation is based on the need for adequate length for a tension free and well-vascularized anastomosis (7). Division at a level just inferior to the left colic artery, with preservation of the left colic artery will result in more predictable blood supply to the anastomosis, but may not give sufficient length, especially in cases where the majority of the sigmoid is resected. Division at the level of the inferior mesenteric artery, at its takeoff from the aorta, along with proximal division of the inferior mesenteric vein, will typically ensure sufficient length for the anastomosis. The anastomosis will then rely on blood supply from the marginal artery of Drummond, based on the middle colic artery. The level of vessel division has not been demonstrated to have an effect on the oncological outcome of the operation (8).