[Anal sphincter-CT and dorsal sphincteropexy - a new approach in therapy of obstructive defecation disorder].

The dysplasia of anal sphincter represents an obstructive defecation disorder. The disease is known as "anterior displaced anus" in pediatric surgery. An anorectal malformation with missing dorsal osseous fixation of the sphincter complex is the underlying cause. Beyond clinical symptoms and examination result (anterior displaced anus with palpable dorsal gap) the defect can be visualized by computered tomography. A surgical correction is possible by the simple intervention of dorsal sphincteropexy. In our trial with 48 patients (male n = 12, female n = 36, mean age 51 +/- 17 years, follow-up in 39 patients) a significant improvement of defecation could be achieved in 46 % of the patients. In correlation to a good clinical outcome a significant reduction in the defecation score was observed. 10 % of the patients had only small changes in symptoms. However, the proportion of dissatisfied patients was relatively high with 44 %. In this group patients with long-standing chronic constipation and laxative abusus were found more often and the rate of previous anal or abdominal surgery was quite higher. Dissatisfied patients showed a higher variation in symptoms of pelvic floor disorders (e. g. anal pain syndrome) besides the rectal evacuation disorder. In addition to the heterogenity of symptoms chronic alterations of pelvic floor structures might create worse results in patients with chronic constipation. In spite of a lot of publications dealing with the functional anatomy of the pelvic floor only a few investigations on the dorsal sphincter dysplasia in patients with rectal evacuation disorder are found in the literature. Further investigations on this disorder are necessary.