Graciloplasty, electrostimulation, electromyography. Clinical implications of electrophysiological phenomena in the neo-sphincter created from the gracilis muscle.

UNLABELLED: The aim of the study was to compare the electrophysiological phenomena occurring in the gracilis muscle, transposed into the pelvic floor during the graciloplasty procedure, subjected to continuous electrical stimulation by means of implanted stimulator, or regular stimulation by means of an external device, as well as the long-term functional results of the graciloplasty procedure.

MATERIAL AND METHODS: A total of 27 patients were included in the analysis. The study group consisted of 7 patients after dynamic graciloplasty, 11 patients after graciloplasty followed by transrectal stimulation, 4 patients after graciloplasty with transcutaneous stimulation, and 5 patients after graciloplasty without any stimulation. All patients had a surface electromyographic examination of the transposed gracilis muscle performed, the signal for each patient was compared to the signal acquisited from a non-transposed gracilis in the same patient. In addition, each subject underwent a clinical operation results assessment, as well as an anorectal manometry examination.

RESULTS: In the electromiographic examination, the mean frequency of motor units action potentials of the gracilis muscle in the thigh was 64 Hz, and in the muscle after transposition and stimulation period mean frequency was 62 Hz. There was no statistically significant difference in the frequency of action potentials before and after treatment in any of the analyzed groups, or between groups with different methods of stimulation (p> 0.05). We found a significant correlation between the clinical outcome of the procedure, and the average amplitude of the EMG signal from the transposed muscle, as well as between the amplitude of the EMG signal and the basal pressure in the anal canal in manometric examination. There were no significant correlations in the remaining manometric parameters.

CONCLUSIONS: Despite the different methods of postoperative stimulation, including expensive implantable stimulators, there was no difference in the electrical activity between the transposed gracilis muscle, and the gracilis muscle left in situ. There was no signoficant advantage of the dynamic graciloplasty procedure over the graciloplasty with transanal or transcutaneous stimulation.