A review on functional results of sphincter-saving surgery for rectal cancer: the anterior resection syndrome.

The aim of this review is to characterize the functional results and "anterior resection syndrome" (ARS) after sphincter-saving surgery for rectal cancer. The purpose of sphincter-saving operations is to save the anal sphincters by avoiding the need for rectal abdomino-perineal resection with a permanent stoma. A variety of alternative techniques have been proposed and, today, ultra-low anterior resections of the rectum are commonplace. Inevitably rectal resections modify anorectal physiology. The backdrop of the functional asset for ultralow anterior resections is related to a small neorectal capacity with high endo-neorectal pressures that act together on a weakened sphincteric mechanism. Sometimes a defecation disorder called ARS may be induced and the patient experiences an extremely low quality of life. Impaired bowel function is usually provoked either by colonic dysmotility, neorectal reservoir dysfunction, anal sphincter damage or by a combination of these factors. Surgical technique defects can contribute to these possible causes: anastomotic ischemia, short length of the descending colon and stretching of neorectal mesentery may play a role. Unfortunately, there is no therapeutic algorithm or gold standard treatment that may be used for ARS. Nevertheless, it is rational to use conservative therapy first and then resort to surgery. Drugs, rehabilitative treatment and sacral neuromodulation may be used; after failure of conservative methods, surgical treatment can be considered.