Laparoscopic low anterior resection (LAR) is used for removal of rectal cancer and benign diseases with the intent of removing the rectum and restoring the continuity of the bowel with an anastomosis in the pelvis. The LAR has been a standard of care for high and mid rectal cancer for many years and, with certain modifications, is now available to individuals with low rectal cancer. This chapter deals with the routine removal of the rectum and its mesentery and the reconstruction of continuity within the pelvis above the anal canal.
Individuals with rectal cancer, diverticulitis, endometriosis, or other less common tumors will require preoperative imaging with computed tomography (CT) scan or transrectal ultrasound to stage the disease and help plan the procedure. In many instances, patients with rectal cancer will require neoadjuvant chemoradiation, which adds another level of complexity to the procedure and will sometimes influence the surgeon to protect the pelvic anastomosis with a temporary diverting loop ileostomy.
A mechanical and antibiotic bowel preparation is usually recommended. The rectum should be emptied of solid stool and irrigated with some form of cytocidal liquid at the beginning of or during the procedure to wash out any malignant cells if the indication is rectal cancer. This serves the purpose of reducing the number of viable cells within the rectal vault, but it has never been definitively shown to decrease the incidence of local recurrence of rectal cancer.
The patient is maintained on bowel rest after midnight before the operation. Broad-spectrum IV antibiotics with coverage of gram-negative aerobes and anaerobes and gram-positive anaerobes are administered prior to incision. Patients are also given subcutaneous low-molecular-weight heparin preoperatively.
General anesthesia with endotracheal intubation is necessary for this operation to provide complete neuromuscular blockade. The patient is supplemented with narcotic analgesia during the anesthetic portion of the procedure to allow a smooth transition to the awakened state. Occasionally, the patient may benefit from an epidural analgesic supplement because of severe chronic obstructive pulmonary disease (COPD). Ketorolac is a reasonable supplement to the narcotic analgesia provided after surgery, if the field is very dry and there is no contraindication to this medication.
Laparoscopic LAR is performed in the lithotomy position using Allen stirrups to position the patient (Figure 1). Sequential compression devices are placed on the calves at the time of entering the room before anesthesia induction. A beanbag is very helpful to fix the patient in position because gravity will be used for retraction. The patient will be tilted back and forth from right to left and placed in steep Trendelenburg and even in reverse Trendelenburg positions at times. The beanbag is curled up around the sides and shoulders of the patient, and a tape is placed across the chest ...