Anorectal atresia with gross terminal colonic distension in Africa

Anorectal malformation (ARM) is a group of significant birth defects with geographic variation in incidence, individual phenotypes and regional geographic subtypes occurring in approximately 1:5,000 live births. Anorectal atresia with gross terminal colonic distension in the presence of an absent anal canal has also been known as 'pouch colon' which is mainly associated with the Indian subcontinent. Its prevalence is unknown but it is rare, possibly representing a fraction of 1 % of ARM. The problem seems to revolve around the gross terminal distension of the distal pouch which remains a significant surgical challenge to surgeons resulting in poorer postoperative continence in many instances.

This study set out to collate data on ARM patients with gross terminal distension of the distal pouch from Africa to evaluate its epidemiology and outcome in African patients.

Fifteen African paediatric surgical centres (7 South African and 8 African centres) were polled on the occurrence of anorectal atresia with gross terminal distension of the terminal bowel, an ARM variant. Data included ethnic group, age, gender as well as the anatomical pathology, classification and presence or absence of associated anomalies.

Of 12 respondents, 8 (67 %) responded and sufficient data to classify and analyse were obtained from six of the eight positive replies (7 new cases). Abdominal X-ray showed a grossly dilated terminal portion of the colon in the presence of an imperforate anus. A colovesical fistula was observed in four (three males and one female cloaca). Three were associated with a colonic atresia, of which two were in the transverse colon and one in the sigmoid colon. Surgical corrective procedures were carried out in six, but one patient, with a cloaca, died prior to surgical correction.

In this survey of 15 African centres, we have attempted to document the occurrence and presentation of anorectal atresia with gross terminal distension in Africa and report seven additional new cases. A possible association with associated conditions like colonic atresia requires further investigation.