Surgical strategy for low rectal cancers.

The two goals of surgery for lower rectal cancer surgery are to obtain clear "curative" margins and to limit post-surgical functional disorders. The question of whether or not to preserve the anal sphincter lies at the center of the therapeutic choice. Histologically, tumor-free distal and circumferential margins of>1mm allow a favorable oncologic outcome. Whether such margins can be obtained depends of TNM staging, tumor location, response to chemoradiotherapy and type of surgical procedure. The technique of intersphincteric resection relies on these narrow margins to spare the sphincter. This procedure provides satisfactory oncologic outcome with a rate of circumferential margin involvement ranging from 5% to 11%, while good continence is maintained in half of the patients. The extralevator abdominoperineal resection provides good oncologic results, however this procedure requires a permanent colostomy. A permanent colostomy alters several domains of quality of life when located at the classical abdominal site but not when brought out at the perineal site as a perineal colostomy.