Considerations on stimulated anal neosphincter formation: an anatomic investigation in search of alternatives to the gracilis muscle.

Abstract

Electrically stimulated anal neosphincter formation with transposed gracilis is performed clinically in an increasing number of patients. The use of a stimulated gluteus maximus in this application has been reported also. The question arises whether or not an optimal design for such a procedure has already been ascertained. An anatomic study was performed on 30 human cadavers to evaluate the semitendinosus muscle and its suitability for construction of a stimulated anal neosphincter. Semitendinosus fulfilled requirements for transposition around the anal canal in all cases. The muscle length was found adequate for transposition; nerve and vascular supply provided a suitable arc of rotation. The pattern of innervation might allow selective stimulation of that particular part of the muscle, which is intended to restore sphincter function. For clinical application, a vascular delay procedure is strongly recommended.