Therapeutic potential of synchronized gastric electrical stimulation for gastroparesis: enhanced gastric motility in dogs

Abstract

The aim of this study was to determine the effects and mechanism of synchronized gastric electrical stimulation (SGES) on gastric contractions and gastric emptying. The first experiment was designed to study the effects of SGES on antral contractions in four randomized sessions. Sessions 1 (control) and 2 (atropine) were performed in the fasting state, composed of three 30-min periods (baseline, stimulation, and recovery). Sessions 3 (control) and 4 (SGES performed during 2nd 20-min period) were performed in the fed state, consisting of two 20-min periods; glucagon was injected after the first 20-min recording. The second experiment was designed to study the effect of SGES on gastric emptying and consisted of two sessions (control and SGES). SGES was delivered with train duration of 0.5–0.8s, pulse frequency of 40 Hz, width of 2 ms, and amplitude of 4 mA. We found that 1) SGES induced gastric antral contractions in the fasting state. The motility index was 1.3 ± 0.5 at baseline and 6.1 ± 0.7 ( P = 0.001) during SGES. This excitatory effect was completely blocked by atropine. 2) SGES enhanced postprandial antral contractions impaired by glucagon. 3) SGES significantly accelerated glucagon-induced delayed gastric emptying. Gastric emptying was 25.5 ± 11.3% without SGES and 38.3 ± 10.7% with SGES ( P = 0.006 vs. control). This novel method of SGES induces gastric antral contractions in the fasting state, enhances glucagon-induced antral hypomotility in the fed state, and accelerates glucagon-induced delayed gastric emptying. The effect of SGES on antral contractions is mediated via the cholinergic pathway.

Mechanisms and Potential Applications of Intestinal Electrical Stimulation

“…The excitatory effect of synchronized IES was blocked by atropine [49]. Similarly, gastric contractions were improved with synchronized gastric electrical stimulation [62] and sequential multi-channel gastric electrical stimulation [63,64]. The excitatory effect of synchronized IES on intestinal contraction is of clinical importance and may be used to treat patients with intestinal hypomotility that is commonly seen in patients with chronic intestinal pseudoobstruction or postoperative ileus.…”

Systematic review: applications and future of gastric electrical stimulation

“…A novel method has recently been proposed: synchronized GES. 98 Synchronized GES requires the implantation of two pairs of electrodes, one for the detection of gastric slow waves and the other for stimulation. In this proposed method, each electrical stimulus was delivered upon the detection of an intrinsic slow wave peak, i.e.…”

“…A recent canine study showed that synchronized GES in fasting state significantly increased the amplitude of gastric contractions and improved the impaired postprandial antral motility induced by glucagons. 98 Apparently, this method can only be applied in patients with normal gastric slow waves but antral hypomotility. It would fail if gastric slow waves were dysrhythmic.…”

Synchronized gastric electrical stimulation improves vagotomy-induced impairment in gastric accommodation via the nitrergic pathway in dogs

“…Dual-pulse GES, combined with both short pulses and long pulses, has advantages of both long-pulse GES and short-pulse GES and is capable of improving dysrhythmia and nausea and vomiting (48). Recently, a number of studies have shown that synchronized GES (or SGES, electrical stimuli are delivered at the occurrence of intrinsic slow waves) has a prokinetic effect: increasing antral contractions and accelerating gastric empty (47,57,59). However, it is unknown whether SGES is able to improve or impair (similar to prokinetics) gastric accommodation, and this is crucial if SGES is to be used for treating gastroparesis and functional dyspepsia, since impaired accommodation is common in these diseases.…”