The right transverse colostomy is preferred by many surgeons for decompression of an obstructed colon due to a left-sided lesion. This procedure completely diverts the fecal stream and permits decompression of the obstructed colon proximal to the lesion. It can also be left in place as the diverting stoma if a low anterior resection is required for middle to lower rectal cancer. When simple diversion of the fecal stream is needed as a complementary component of an elective colonic operation, the surgeon should consider placement of a proximal diverting loop ileostomy (see Chapter 55).
Because this procedure is usually performed to relieve acute obstruction of the left colon, preoperative preparation is limited to correction of fluid and electrolyte imbalance as well as blood volume deficits. Flat and upright roentgenograms of the abdomen can be sufficient to make the diagnosis, although a water-soluble contrast material enema can be performed to locate conclusively the left-sided point of obstruction. Alternatively, a computed tomography scan of the abdomen and pelvis frequently can provide all the necessary information. Prophylactic antibiotics are administered intravenously within 1 hour of incision. When possible, preoperative marking of possible stoma sites by an enterostomal therapist can greatly decrease the morbidity of the stoma. The tentative site should be checked with the patient standing and sitting and taking special note of the proximity to the patient's beltline, which should be avoided.
Usually endotracheal anesthesia, which provides a cuff for secure closure of the trachea, is indicated to avoid aspiration of regurgitated gastrointestinal contents.
The patient is placed in a comfortable supine position with the proposed site for the incision presenting. Then a time-out is performed.
A laparotomy is often required to obtain adequate visualization of the distended colon. It also allows for inspection of the cecum, which is the portion of the colon most at risk of having already undergone perforation or necrosis due to the obstruction. Mobilization of the transverse colon during a laparotomy is akin to the steps shown in FIGURES 1, 2, 3 with a separate trephine made in the abdominal wall for the colostomy at a preoperatively marked site.
Alternatively, as shown in FIGURES 1, 2, 3 the colostomy can be created through one minilaparotomy incision. The incision is placed in the right upper quadrant. A vertical or transverse incision can be made in a location over the distended colon, as based on study of the abdominal roentgenograms. Currently, it is believed that the opening should be made through the rectus muscle, with consideration being given to the span of the ostomy appliance gasket, which should be away from skin folds, bony prominences, or the valley of the umbilicus. The opening ...