Stimulated gracilis neosphincter: a new procedure for anal incontinence

The gracilis muscle has been used previously to construct an anal neosphincter, but this was not successful since a short-lived muscle contraction was insufficient to restore continence. Recently, a procedure was described in which conversion to a fatigue-resistant muscle was achieved by chronic low frequency electrical stimulation, and the resultant ability to sustain a constant contraction was associated with improved continence. Our initial results with this procedure, using a standardized operation and treatment protocol in 12 consecutive patients, is reported.

Seven women (mean age 50 years, range 22-71 years) had faecal incontinence, and five patients (F:M, 3:2; aged 53-72 years) underwent reconstruction after abdominoperineal excision of the rectum for cancer. A detailed questionnaire including continence score was completed pre-operatively. Eight patients have been assessed after ileostomy closure at a mean time of 10 months.

Slow-twitch muscle conversion was achieved in each case and all patients have a functional neosphincter. Mean continence score was 6.8 (range 4-12), and seven patients were continent. There was significant improvement in continence in the non-cancer group (p = 0.03). Mean pre-operative resting anal pressure, functional neosphincter pressure (NPfunc), and maximal neosphincter pressure (NP(max)) were 36, 102 and 207 cmH2O, respectively. There was a significant improvement in pressure comparing NPfunc (P = 0.03) and NP(max) (P = 0.03) with pre-operative pressure. Complications included deep vein thrombosis, pulmonary embolism, saphenous nerve injury, leg wound haematoma, and late pacemaker infection.

The stimulated gracilis neosphincter achieves satisfactory continence in a majority of patients.