Plate 81

The stapler offers certain advantages in the performance of a low anterior resection, provided the surgeon is thoroughly familiar with the technique. Those favoring this method of approximating the sigmoid to a short rectal stump emphasize the ease of the anastomosis, especially in the narrow pelvis of the male. The time required for the operation may be shortened and the indications for a temporary proximal diverting loop ostomy decreased. Use of the stapler does not alter the principles of adequate resection of tumors at approximately 8 cm or less from the anus. This is because anastomoses lower than 3 cm from the anus may be associated with incontinence and because a distal margin of 2 to 3 cm below the cancer is recommended to minimize the rate of local anastomotic recurrence. The success of a properly performed anastomosis depends on an adequate blood supply to the residual bowel segments, which can be brought together easily without tension. Cancers below the peritoneal reflection in the pouch of Douglas should be evaluated with endorectal ultrasound for their staging and spread. Preoperative radiation therapy and chemotherapy should be considered for these lesions.

An empty colon results from one day of liquid diet. The usual bowel preparation is given the day prior to surgery, while parenteral antibiotics are administered just prior to the start of the procedure. Since the stapler is to be introduced through the anus, it is mandatory that the lower colon and rectum be carefully emptied and cleansed just before the procedure is started. A large mushroom catheter commonly is introduced into the rectum for a saline irrigation until clear. Several ounces of a mild antiseptic solution such as 10% povidone-iodine can be instilled at the time the procedure is started. An inlying bladder catheter is essential for good exposure.

General endotracheal anesthesia is satisfactory.

The patient is placed in a semilithotomy position using Allen stirrups and in a modest Trendelenburg position to enhance exposure of the deep pelvis and permit the introduction of the stapling instrument via the anus.

Not only the abdominal wall from the xiphoid to the pubis, but the skin over the perineum, groin, and especially the anal region are prepared since the instrument will be introduced through the anus.

A long midline incision is made starting just above the symphysis and extending to the umbilicus and around it on the left side to provide easy access to the splenic flexure (Figure 1). The liver is palpated for possible metastasis, and the location and mobility of the growth as well as the presence or absence of metastatic lymph nodes are verified by palpation. The small intestine may be placed in a plastic Lahey bag to which some saline solution is added. The mobility of the transverse and descending colon is evaluated with special reference to the adequate exposure of the splenic flexure. Undue traction on the omentum or colon in the region of the spleen may result in troublesome bleeding from a tear in the splenic capsule, hence many surgeons routinely mobilize the splenic flexure.

The indications for an anterior resection are reconfirmed, and the sigmoid and transverse colon are mobilized using the same incision and exposure techniques as in Plate 80 (Figure 2 & 3). A high ligation of the inferior mesenteric lymphovascular pedicle is carried out following exposure and clear identification of the left gonadal vein and ureter. The sigmoid artery is ligated near the inferior mesenteric artery with preservation of the arcade between the ascending and descending branches of the left colic artery. The mesentery of the left colon is divided over to the junction of the sigmoid and descending colon (Figure 2).

Two methods of stapled closure are presented.

A point on the sigmoid is selected for division, and the mesenteric border is meticulously cleared for a distance of approximately 2 cm (Figure 3). Active pulsations must be present in the mesentery, and the cleared area must be free of diverticuli. A total mesorectal excision (Plate 70) is carried out to at least 2 cm, preferably 5 cm, below the tumor. A linear stapler is fired across the rectum at that level (Figure 4) and the mesorectum is divided. Some staplers close both sides while cutting between the staple lines, while others fire only one line of staples and hence require a clamp on the proximal (“specimen”) side. The rectosigmoid specimen is then lifted out of the pelvis.

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