Anal canal duplication in infants and children--a series of 6 cases.

The authors present a series of six anal canal duplications (ACD), duplications of the alimentary tract located along the posterior side of the anal canal, with a perineal opening just behind the anus. Five asymptomatic duplications were diagnosed before the age of one year, by simple perineal inspection. A twelve-year-old girl presented with perineal and anal pains and diarrhoea. Fistulography revealed a tubular structure in five cases and a cystic structure in one case, behind the normal anal canal, in one case communicating with it. A presacral sacrococcygeal teratoma was found in two children and in one case it was visualised by preoperative US in an infant with a lumbosacral myelomeningocele. Surgical excision was performed by a perineal approach in 5 cases, by a combined sacral and perineal approach in the last case, because of the associated teratoma. Non-invasive preoperative investigations, consisting of a pelvic X-ray, US examination, barium enema and fistulography, are sufficient in most cases; MRI is reserved for special indications. Surgical treatment restores a normal perineal aspect, without sequelae, and avoids complications like those described in other types of digestive duplications: infection, ulceration, bleeding, malignant changes during later adult life. Associated anomalies are frequently described in the literature, especially presacral tumours (16%) and anorectal malformations (21%); they can influence the management, the surgical approach and the functional prognosis.