INFLUENCE OF ELECTRICAL STIMULATION ON FUNCTION OF THE LOWER ESOPHAGEAL SPHINCTER IN PATIENTS WITH GASTROESOPHAGEAL REFLUX DISEASE

Study aims. Recently the possibility of LES tonus increasing by the means of implantable electrical stimulator was described. Although this method is already used in clinical practice, optimal parameters of LES electrical stimulation are still unknown. The goal of this study was obtaining of clinical data regarding effects of different modes of electrical stimulation on LES tonus. Methods. LES electrical stimulation using external pulse generator was assessed in 9 patients with severe GERD and decreased LES tonus. These patients underwent standard laparoscopic antireflux intervention with additional insertion of 2 temporary electrodes at the level of gastroesophageal junction. Three sets of parameters were studied: 1) low-frequency, long pulse (375 ms pulses, 5 mA at 6 pulse/min); 2) high-frequency stimulation (0.3 ms, 5 mA at 20 Hz); 3) high-frequency at 40 Hz (0.3 ms, 5 mA). High resolution esophageal manometry was used to assess changes in LES tonus. Results. Values of LES resting pressure and integrated relaxation pressure (IRP) were significantly different between prestimulation and poststimulation periods. The low-frequency, long pulse stimulation produces improvement of esophagogastric junction relaxation in the poststimulation period. Patients stimulated with the second and the third sets of parameters demonstrated moderate relaxation of LES during the stimulation period and considerable increase of sphincter tonus in the poststimulation period. Conclusions. Electrical stimulation of LES produces changes in its tonus. Modifications of LES function during the stimulation and after the stimulation period depend on frequency and pulse width. Further clinical studies are necessary for selection of optimal stimulation parameters, which can be applied in the treatment of GERD.

lower esophageal sphincter, electrical stimulation, gastroesophageal reflux disease

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