Stimulated graciloplasty for treatment of intractable fecal incontinence: critical influence of the method of stimulation.

Introduction: Patients with end-stage fecal incontinence, in whom all standard medical and surgical treatment has failed or is not expected to be effective, can be treated by stimulated graciloplasty. The aim of the present study was to assess the efficacy of stimulated graciloplasty by both direct nerve and intramuscular perineural stimulation techniques and to evaluate various parameters relative to outcome.

Methods: A prospective analysis of all patients who underwent this procedure was undertaken. All patients were preoperatively investigated by anal manometry, electromyography, pudendal nerve terminal motor latency assessment, endoanal ultrasound, and an enema retention test. They were further assessed with an incontinence scoring system and a Quality of Life Questionnaire. Postoperative evaluation included anorectal manometry, incontinence score registry, and a Quality of Life Questionnaire. In our initial experience the stimulation system electrodes were fixed directly to the nerve (direct nerve stimulation graciloplasty); later in the study the stimulation system electrodes were fixed intramuscularly close to the nerve branches (intramuscular perineural stimulation graciloplasty).

Results: From May 1993 to February 1998, 27 patients underwent 33 gracilis transpositions for fecal incontinence, 30 of which were stimulated. Six of the patients with direct nerve stimulation graciloplasty eventually had the direct nerve stimulator removed and replaced with an intramuscular electrode stimulator. After an mean follow-up (until the time of exit from study) of 12.5 (range, 1-23) months for direct nerve stimulation graciloplasty and 21 (range, 8-27) months for intramuscular perineural stimulation graciloplasty, 13 graciloplasties (43 percent) were successful. There was no correlation between outcome of surgery and age, duration or cause of symptoms, body habitus, manometric or electromyographic parameters, prior sphincter repair, the presence of a pre-existing stoma, or any immediate postoperative complications. However, the number of patients with intramuscular perineural stimulation graciloplasty who had a successful outcome (continent, 69 percent; improved but not fully continent, 23 percent; incontinent, 8 percent) was significantly higher than patients with direct nerve stimulation graciloplasty (improved but not fully continent, 10 percent; incontinent, 90 percent).

Conclusion: The success of stimulated graciloplasty is dependent on the method of nerve stimulation, whereas surprisingly, none of the many other factors assessed influenced outcome.