Comparison of epineural or intramuscular nerve electrodes for stimulated graciloplasty

Two different techniques have been developed to stimulate the gracilis muscle when it is used in anal neosphincter reconstruction. These are direct neural stimulation and intramuscular electrode stimulation. The aim of this study was to compare these techniques.

Comparison was made of gracilis anal neosphincter reconstruction using neural stimulation (Royal London Hospital in the United Kingdom) with the intramuscular muscular method (University Hospital Maastricht in the Netherlands). The United Kingdom data were obtained from a retrospective database, whereas the Netherlands data were gathered prospectively.

A successful outcome was achieved 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 no significant difference between the two techniques in voltage required for stimulation of the neosphincter muscle during a ten-year period. Reoperative surgery for electrode failure or dislocation was required in 21 (26 percent) patients in the London study, whereas only four (2.7 percent) of the Maastricht cases required such procedures (chi-squared = 37.8; P < 0.05). The high electrode plate failure rate in the London study was related to the source of manufacture.

Both neural and intramuscular nerve techniques provide effective long-term stimulation of the gracilis anal neosphincter.