The long head of the biceps femoris: anatomic basis for its possible use in the construction of an electrically stimulated neoanal sphincter.

Electrical stimulation of the nerve to the gracilis muscle following its transposition around the anal canal creates an artificial sphincter capable of actively opposing intrarectal pressure. Not all patients have an available or suitable gracilis. This paper describes the anatomic basis for the use of the long head of the biceps femoris as a potential electrically stimulated neoanal sphincter. The muscle was found to have an adequate length and a suitable arc of rotation for transposition around the anal canal. In 75 percent of thighs studied the neurovascular anatomy of the long head of the biceps femoris was compatible with its utilization in this manner as an alternative to the gracilis.