Electromyographic studies on the external anal sphincter in children with operated anorectal malformations.

Fecal incontinence is a common problem after surgical repair in patients with anorectal malformations. A normally functioning external anal sphincter (EAS) mechanism is a major factor for continence. The aim of this study was to assess the function of the EAS in children with operated anorectal malformations by electromyography (EMG) and to refine the sphincter function further. The study group consisted of 8 patients with incontinence problems who were operated for anorectal malformations. The electrical activity of EAS was evaluated by EMG using concentric needle electrodes in all subjects. The presence, localization, integrity and activity of the sphincter were assessed. Seven of 8 patients showed electrical activity of the EAS. Sphincter localization was found to be appropriate in six children. Five children showed a well preserved sphincter integrity and 2 of them disclosed normal EMG activity. In cases of localization or integrity abnormalities, secondary corrective surgery was planned, while in patients showing only abnormal EMG activity, biofeedback treatment was given. In cases of fecal incontinence in patients with operated anorectal malformations, electromyographic study shows the type of sphincter abnormality and further helps to make a decision whether to improve the EAS function with conservative treatment or surgically.