NMS. Casos Clínicos

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Chapter 8 ♦ Lower Gastrointestinal Disorders

Colon Rectum

Rectum Colon

A B Figure 8-29: Low anterior bowel resection, showing (A) staple technique and (B) suture technique. (From Greenfield LJ, Mulholland MW, Oldham KT, et al, eds. Surgery: Scientific Principles and Practice , 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 1997:1141.)

Q: When might preoperative radiation therapy be a consideration? A: If lesions are large and bulky or extend outside the bowel wall into the surrounding tissue, the rate of local recurrence is higher. Thus, management usually involves preoperative irradiation and chemotherapy to increase resectability and decrease local recurrence. Q: What alternatives do patients have if they do not agree to colostomy? The procedures previously described in this case are the standard methods for treatment of rectal cancer, but there are two additional therapeutic options. A: One approach is sphincter-preserving proctectomy (Fig. 8-30). A rationale for this pro- cedure relates to a change in thinking about the distal resection margin necessary to cure a patient with cancer. Previously, experts believed a 5-cm distal margin was necessary, but more recently, studies have found that a 2-cm margin is adequate for well-differentiated cancers. Additional improvements have occurred in the operative approach and with the preservation of anal continence. Combined with preoperative radiation and chemotherapy to the rectum and a temporary diverting ileostomy to allow anastomotic healing to occur, these procedures have become commonplace. A second approach involves local resection of rectal tumors. In these cases, one method involves dilation of the anal sphincter and resection of the tumor. Another method in- volves using a trans-sacral approach to the rectum, which allows a sleeve resection of the tumor-bearing bowel (Fig. 8-31). Both approaches are particularly useful for small tumors in high–medical risk patients. Carcinomas that are less than 4 cm in diameter and involve less than 40% of the rectal wall can be resected through a transanal approach. This approach is usually reserved for T1 lesions. Q: How does abdominoperineal resection differ in women? A: In female patients with anterior rectal wall carcinoma, removal of the posterior vagina is appropriate. Surgeons should be careful not to denervate the urethra. Closure of the vagina may then occur. A patient undergoes a curative resection with an abdominoperineal resection. SAMPLE