Surgical approaches to anal incontinence

Primary repair of acute anal sphincter injuries by direct apposition of the severed external sphincter without tension is advisable whenever feasible. However, the majority of patients who are candidates for surgical treatment of anal incontinence will undergo a secondary repair, the type of which will depend on the underlying aetiology and the surgeon's preference and experience. The most successful of these procedures is sphincter reconstruction with or without levatoroplasty for a disrupted anal sphincter (due to surgical, obstetrical or other trauma) in the absence of underlying neurological damage. Success rates are reported at 80-90%. Post-anal repair is advocated for patients with a poorly functioning sphincter with an obtuse anorectal angle, most of whom have a neurogenic basis for their incontinence. Success rates vary from 60 to 75% of cases but long-term results have been less satisfactory. Rectal procidentia is associated with faecal incontinence in 65-75% of cases. Abdominal repair (we favour suture rectopexy with sigmoid resection) restores continence in 50-80% of such patients. Patients with persisting incontinence are candidates for post-anal repair. Anal encirclement with an elastic, Dacron-impregnated Silastic sleeve has a limited role in selected patients. For more severe incontinence, muscle transfers (gracilis, gluteus maximus, etc.) can achieve some success but continence is less than perfect. We are currently assessing the use of an artificial anal sphincter (a modification of the AMS 800 urinary sphincter). For patients who fail all therapeutic options, a stoma will provide a better lifestyle than coping with the consequences of faecal incontinence.