Endosonographic study of anal sphincters in patients after surgery for Hirschsprung's disease

Purpose: This study was performed to evaluate the relationship between endo sonographic findings of anal sphincters and anorectal function in patients after surgery for Hirschsprung's disease. In addition, whether internal sph incterotomy or sphincterectomy was accomplished was examined in each proced ure by anal endosonography. Methods: Fifteen patients, aged 11 to 20 years, were examined. Nine patient s underwent modified Duhamel's operation, three underwent Rehbein's operati on with anorectal myectomy, and three underwent modified Martin's operation . All 15 patients were examined by anal endosonography using a sonographic scanner (Aloka SSD 2000) with a 7.5-MHz radial rotating endoprobe, clinical bowel assessment, and manometric study. Results: After the modified Duhamel operation, anal endosonography showed a n interruption of the external anal sphincter (EAS) in eight of the nine pa tients, as a high, mixed, or low echoic lesion in the hyperechoic band corr elated to the EAS. The locations of the interruption were wide in patients with mild constipation. An interruption of the internal anal sphincter (IAS ) was observed in all nine patients, as a hyperechoic lesion in the hypoech oic band correlated to EAS, which indicated internal sphincterotomy. After Rehbein's operation with anorectal myectomy, an interruption of EAS was obs erved in all three patients as a high or low echoic lesion in the hyperecho ic band. An interruption of IAS was observed in all three patients. After t he modified Martin's operation, an interruption of EAS was observed in two of the three patients as a high or low echoic lesion in the hyperechoic ban d. An interruption of IAS was observed in all th ree patients. Conclusion: Anal endosonography showed detailed distributions of EAS and IA S in patients after surgery for Hirschsprung's disease and complete interna l sphincterotomy or sphincterectomy after these operations. Copyright (C) 1 999 by W. B. Saunders Company.