Anorectal atresia

December 31, 2014

Synonyms

Overview

Anorectal atresia is birth defect in which the rectum is malformed. It is a spectrum of different congenital anomalies in males and females, that varies from fairly minor lesions to complex anomalies.

Symptoms

Infant death
Stillbirth
Fetal death
Absent anal opening
Inability to move fecal waste

Causes

The cause is unknown; the genetic basis of these anomalies is very complex because of their anatomical variability. In 8% of patients genetic factors are clearly associated with this disease. Anorectal malformation in Currarino syndrome represents the only association for which the gene HLXB9 has been identified.

Diagnosis

When an infant is born with an anorectal malformation, it is usually detected quickly as it is a very obvious defect. Doctors will then determine the type of birth defect the child was born with and whether or not there are any associated malformations. It is important to determine the presence of any associated defects during the newborn period in order to treat them early and avoid further sequelae. There are two main categories of anorectal malformations: those that require a protective colostomy and those that do not. The decision to open a colostomy is usually taken within the first 24 hours of life.

Prognosis

With a high lesion, many children have problems controlling bowel function and most also become constipated. With a low lesion, children generally have good bowel control, but they may still become constipated. For children who have a poor outcome for continence and constipation from the initial surgery, further surgery to better establish the angle between the anus and the rectum may improve continence and, for those with a large rectum, surgery to remove that dilated segment may significantly improve the bowel control for the patient. An antegrade enema mechanism can be established by joining the appendix to the skin (Malone stoma); however, establishing more normal anatomy is the priority.

Treatment

requires immediate surgery to open a passage for faeces. Depending on the severity of the imperforate, it is treated either with a perineal anoplasty or with a colostomy.