gracilis neoanal sphincter (transposition)

Last reviewed 01/2018

A functional sphincter may be restored to the anus by the transposition of one of the patient's gracilis muscles in a subcutaneous loop around the external surface of the tract at this point. The free end of the gracilis muscle is sutured to the contralateral ischial tuberosity.

Contraction of the muscle maintains continence. It is continuously stimulated by a buried device that activates the obturator nerve. Defaecation is permitted by using an external magnet to switch the device off.

A neoanal gracilis sphincter is indicated in:

  • irreversible damage to the pudendal nerve, e.g. after chronic constipation and prolonged second stage of labour
  • after perineal excision of an anorectal tumour