Left colectomy describes resection of the colon from the mid-transverse colon to the junction of the descending and sigmoid colon. Typically, the proximal extent of the procedure would include the left branch of the middle colic vessels, and thus the proximal margin may be to the right of the midline abdomen and falciform ligament, as the middle colic origin is to the right of the midline. The distal extent has no rigid anatomic definition, but is approximately where the descending colon loses its close approximation to the left lateral sidewall of the abdomen, and the sigmoid colon begins its meandering course away from the left lateral peritoneal reflection. Sigmoid colectomy refers to resection of the colon from the junction with the descending colon to the rectosigmoid junction or proximal rectum. Again, this latter landmark has variable definitions. The two most useful definitions are: “where the colonic taenia coalesce” as this can be confirmed by visual inspection, and the other definition is practical, namely, “just below the sacral promontory,” as it is possible to advance a circular (endoanal anastomosis—EEA) stapler to this level.

Naming conventions for laparoscopic colorectal procedures can be varied. The following terminologies are used in this chapter. An operation is laparoscopic if the resection is performed laparoscopically and the main incision is no larger than required to extract the colon specimen.

Laparoscopic-assisted implies that a portion of the case is performed extracorporeally, for example, for a sigmoid resection, once the sigmoid colon is mobilized it is extracted via a 3- to 5-cm periumbilical incision, the proximal resection margin is transected extracorporeally, and the anvil of the EEA stapler is secured with a purse-string suture to secure the anvil, before returning the bowel to the peritoneal cavity to perform the anastomosis under laparoscopic visualization. The incision, however, is usually identical to that used to extract the specimen, so this differentiation is meaningless in terms of incision length.

The other two terms are hand-assisted and hybrid procedures. The author does not believe that these techniques demonstrate “mastery” of surgery, and thus these terms are mentioned here only to be complete. The author believes that these approaches may be useful for the beginner who is adopting these procedures, as a bridge to learning advanced operations, but these techniques are not a substitute for learning advanced techniques and are not used in our fellowship program. In a hand-assisted procedure a 6- to 8-cm incision (the number of centimeter is equal to the surgeon’s glove size) is used to place a device that allows a hand to be inserted into the peritoneal cavity to facilitate the procedure. This is larger than the typical 3- to 5-cm incision used to extract the specimen for a laparoscopic or laparoscopic-assisted operation. In a hybrid procedure, part of the case is performed laparoscopically and part is deliberately performed open, for example, laparoscopic mobilization of the descending colon and splenic flexure in a planned sigmoid resection, followed by resection and anastomosis through a small incision (infraumbilical midline or Pfannenstiel).

Performing a laparoscopic operation is facilitated by correct positioning. There are three key points: (a) steep position changes are used so that the patient must be safely secured to the table; (b) access to the perineum may be required for stapled anastomosis or intraoperative endoscopy; and (c) the position must allow instruments to be used through any of the ports. To ensure that the patient does not slip, a table is prepared with medical grade pink “egg-crate” foam taped to the bed over a drawer sheet placed beneath the foam, to be used for tucking the arms. The patient is placed in a modified combined synchronous position (modified lithotomy). Padded Allen stirrups are used to position the legs so that the thighs have 5 degrees of flexion and are almost parallel to the abdominal wall. This ensures that instruments used in the lower trocars during dissection in the upper abdomen are not hampered by the thighs. The hands are wrapped in foam and tucked adjacent to the torso. A warming blanket is placed over the chest, followed by a folded blanket (to prevent tearing of the warming blanket so that it may be used in the recovery room), and linen tape is wrapped around the patient’s chest and around the table three times. A “tilt test” is then performed by moving the OR table into all the potential extreme positions used during the case to ensure that the patient is safely secured. Bladder and gastric decompression are obtained with a Foley catheter and orogastric tube respectively, the latter being removed at the end of the case.

This technique uses a lateral-to-medial approach, for several reasons. First, the approach is similar to the open approach and trainees recognize the anatomic landmarks more readily. Second, a medial-to-lateral approach involves sacrificing the IMA and the IMV. Although the IMA requires division in the case of sigmoid colon cancer (to obtain an adequate lymphadenectomy specimen), the author’s preference is to preserve it in benign disease, for example, diverticulitis, by dividing the mesentery close to the colon and thus preserving the superior rectal blood supply to the rectal stump. Proximal division of the IMV is not required as part of an oncologic approach, and it is divided selectively, if required, to obtain adequate length of the proximal colon margin to obtain an anastomosis without tension. Third, in a medial-to-lateral approach, the colon is devascularized early in the case leaving ischemic bowel in situ while the case proceeds.

Whether a sigmoid or a left colectomy is being performed, the full mobilization of the left colon is essentially the same. The author routinely mobilizes the splenic flexure for a sigmoid colectomy as this ensures a tension-free anastomosis and facilitates exteriorization of the specimen. Essentially, the sigmoid and descending colon and the splenic flexure are fully mobilized, followed by a decision regarding transection margins in the colon and the vasculature.