Comparison of epineural or intramuscular nerve electrodes for stimulated graciloplasty

OBJECTIVE: Two different techniques have been developed to stimulate the gr acilis muscle when it is used in anal neosphincter reconstruction. These ar e direct neural stimulation and intramuscular electrode stimulation. The ai m of this study was to compare these techniques. METHODS: Comparison was ma de of gracilis anal neosphincter reconstruction using neural stimulation (R oyal London Hospital in the United Kingdom) with the intramuscular muscular method (University Hospital Maastricht in the Netherlands). The United Kin gdom data were obtained from a retrospective database, whereas the Netherla nds data were gathered prospectively. RESULTS: A successful outcome was ach ieved in 46 of 81 patients (57 percent) in London and 148 of 200 cases (74 percent) in the Maastricht study (chi-squared = 7.2; P < 0.01). There was n o significant difference between the two techniques in voltage required for stimulation of the neosphincter muscle during a ten-year period. Reoperati ve surgery for electrode failure or dislocation was required in 21 (26 perc ent) patients in the London study, whereas only four (2.7 percent) of the M aastricht cases required such procedures (chi-squared = 37.8; P < 0.05). Th e high electrode plate failure rate in the London study was related to the source of manufacture. CONCLUSIONS: Both neural and intramuscular nerve tec hniques provide effective long-term stimulation of the gracilis anal neosph incter.