The operation is performed chiefly for tumor of the left colon or a complication of diverticulitis.
Tumors of the left colon are frequently of the stenosing type. Patients with this condition often come to the surgeon with symptoms of impending intestinal obstruction.
When obstruction is not complete, the bowel can best be prepared over a period of days by oral administration of the appropriate cathartics and a clear liquid diet for the last 48 hours. The frequency with which cathartics and cleansing agents are administered will vary depending upon the amount of obstruction. The level and nature of the obstruction may be confirmed by barium enema; however, colonoscopy allows biopsy for pathologic identification, identification and removal of additional lesions such as polyps, and potential evaluation of the proximal colon. In the presence of total obstruction, a nasogastric tube is passed for decompression and the colon is emptied from below with enemas. Evaluation of the distal colon with colonoscopy is valuable and a virtual colonoscopy may be obtained with special CT imaging to evaluate the proximal colon. A baseline carcinoembryonic antigen (CEA) blood test is obtained. If this and enzymatic liver function tests are elevated, CT or imaging scans of the abdomen and liver may be obtained to evaluate metastatic spread. Perioperative antibiotics are given. A Foley catheter is inserted after induction of anesthesia.
General anesthesia is preferred.
The patient is placed in a comfortable supine position and rotated slightly toward the operator. A slight Trendelenburg position may be used, although it can rarely lead to lower extremity compartment syndrome. If the colon tumor or process is in the lower left colon or sigmoid region, most surgeons will position the patient in a modified lithotomy manner using Allen stirrups supporting the knees and ankles. This will allow for prepping ...