An incision is made in the peritoneal reflection close to the lateral wall of the bowel from the tip of the cecum upward to the region of the hepatic flexure (Figure 1). A liberal margin should be ensured in the region of the tumor. Occasionally, the full thickness of the adjacent abdominal wall may require excision to include the local spread of tumor. Since the entire hepatic flexure is usually removed as part of a right colectomy, the hepatocolic ligament, which contains some small blood vessels, must be divided and ligated, but there will be no blood vessels of importance in the peritoneal attachments along the right gutter. With the lateral peritoneal attachment divided, the large bowel may be lifted mesially with the left hand, while the loose areolar tissue lying under it is dissected off with a moist gauze sponge over the right index finger (Figure 2). In elevating the right colon toward the midline, the surgeon must positively identify the right ureter and be certain that it is not injured. Care is taken also toward the top of the ascending colon and near the hepatic flexure to avoid injury to the third portion of the duodenum, which underlies the large bowel (Figure 3). The raw surface remaining after the intestine has been freed and brought outside the peritoneal cavity is covered with warm, moist gauze pads. The middle colic vessels are identified, along with the right-hand branches heading toward the hepatic flexure and the planned zone of transection. The mesentery of the large bowel is clamped and divided just distal to the hepatic flexure or wherever the bowel is to be resected. The right branches or all of the middle colic vessels are divided and doubly ligated. The bowel at the selected level for division is freed of all mesentery, omentum, and fat on both sides. All vessels must be carefully ligated. The right half of the greater omentum is divided near the greater curvature of the stomach and excised along with the right colon.