A comparison of anal endosonography with electromyography and manometry in high and intermediate anorectal anomalies

Anal endosonography, electromyography (EMG) of the external anal sphincter (EAS), and manometry of the internal anal sphincter (IAS) were performed in 15 patients with anorectal anomalies (10 with high and five with intermediate anomalies), ranging in age from 8 to 18 years. The anal endosonographic findings were compared with those for the EMG of the EAS and manometry of the IAS. An image including the hyperechoic band that corresponds to the EAS was obtained in all 15 patients. However, the distribution of EAS image was inadequate in high anomalies. In four patients who showed in Kelly score of 5 or 6, good visualization of the EAS was obtained in both anal endosonography and EMG. An Image including the hypoechoic band that corresponds to the IAS was obtained in five patients with high anomalies and in one with intermediate anomalies. Therefore, even in patients with anomalies, at these levels the IAS could be ultrasonically detected. However, only one of these six patients exhibited an anorectal reflex. These results indicate that, for the EAS, the findings of anal endosonography correspond well with those of EMG, but that for the IAS, they do not correspond with those of manometry. At the time of surgery for anorectal anomalies care should taken to preserve the IAS, which can be detected by anal endosonography even in patients with high or intermediate anomalies.