We conclude that GES is more effective in improving long-term GI symptoms and costs, and decreasing use of healthcare resources than intensive medical therapy, in this sample of patients with the symptoms of GP followed for 3 years. Certain patients with GP form a high-risk group in terms of costs, quality of life, morbidity and mortality.

Background: Drug-refractory gastroparesis has previously been without acceptable alternative therapies. Although gastric electrical stimulation has been used for over a decade, no long-term multicenter data exist. Methods: We studied 214 consecutive drug-refractory patients with the symptoms of gastroparesis (146 idiopathic, 45 diabetic, 23 after surgery) who consented to participate in a variety of clinical research and clinical protocols at three centers from January 1992 through January 2005, resulting in 156 patients implanted with a gastric electrical stimulation device and the other 58 patients serving as controls. The patients were stratified into three groups: (1) consented but never permanently implanted; (2) implanted with permanent device, and (3) consented while awaiting a permanent device. The patients were followed over time for gastrointestinal symptoms, solid gastric emptying, health-related quality of life, survival, device retention, and complications. Demographics, descriptive statistics, and t tests were used for comparison between baseline and latest follow-up. Results: At latest follow-up, median 4 years for 5,568 patient months, most patients implanted (135 of 156) were alive with intact devices, significantly reduced gastrointestinal symptoms, and improved health-related quality of life, with evidence of improved gastric emptying, and 90% of the patients had a response in at least 1 of 3 main symptoms. Most patients explanted, usually for pocket infections, were later reimplanted successfully. There were no deaths directly related to the device. Conclusion: Based on this sample of patients, implanted with gastric electrical stimulation devices at three centers and followed for up toward a decade, gastric electrical stimulation for drug-refractory gastroparesis is both safe and effective.

In isolated perfused rat hearts, epidermal growth factor (EGF; 15 nM) increased cellular cyclic AMP (cAMP) content by 9.5-fold. In rat cardiac membranes, EGF also stimulated adenylate cyclase activity in a dose-dependent manner, with maximal stimulation (35% above control) being observed at 10 nM-EGF. Half-maximal stimulation of adenylate cyclase was observed at 40 pM-EGF. Although the beta-adrenergic-receptor antagonist propranolol markedly attenuated the isoprenaline-mediated increase in cAMP content of perfused hearts and stimulation of adenylate cyclase activity, it did not alter the ability of EGF to elevate tissue cAMP content and stimulate adenylate cyclase. The involvement of a guanine-nucleotide-binding protein (G-protein) in the activation of adenylate cyclase by EGF was indicated by the following evidence. First, the EGF-mediated stimulation of adenylate cyclase required the presence of the non-hydrolysable GTP analogue, guanyl-5'-yl-imidodiphosphate (p[NH]ppG). Maximal stimulation was observed in the presence of 10 microM-p[NH]ppG. Secondly, in the presence of 10 microM-p[NH]ppG, the stable GDP analogue guanosine 5'-[beta-thio]diphosphate at a concentration of 10 microM blocked the stimulation of the adenylate cyclase by 1 nM- and 10 nM-EGF. Third, NaF + AlCl3-stimulated adenylate cyclase activity was not altered by EGF. The ability of EGF to stimulate adenylate cyclase was not affected by pertussis-toxin treatment of cardiac membranes. However, in cholera-toxin-treated cardiac membranes, when the adenylate cyclase activity was stimulated by 2-fold, EGF was ineffective. Finally, PMA by itself did not alter the activity of cardiac adenylate cyclase, but abolished the EGF-mediated stimulation of this enzyme activity. The experimental evidence in the present paper demonstrates, for the first time, that EGF stimulates adenylate cyclase in rat cardiac membranes through a stimulatory GTP-binding regulatory protein, and this effect is manifested in elevated cellular cAMP levels in perfused hearts exposed to EGF.

Background and Aims Factors underlying gastroparesis are not well defined, nor is the mechanism of action of gastric electrical stimulation (GES). We hypothesized that GES acts via several mechanisms related to underlying disordered pathophysiology. Methods We studied 43 consecutive eligible patients with gastroparetic symptoms, previously evaluated by two methods in each of five core areas: inflammatory, autonomic, enteric, electrophysiologic, and hormonal; and also categorized by GI symptoms, metabolic status, illness quantification, and gastric physiology. We then studied 41 patients who underwent temporary GES for 5‐7 days. Thirty‐six of those patients were implanted and 30 were followed up at 6 months after permanent GES. Results In previous but separately reported work, patients had similar GI symptoms regardless of baseline gastric emptying or diabetic/idiopathic status and all patients demonstrated abnormalities in each of the five areas studied. After GES, patients showed early and late effects of electrical stimulation with changes noted in multiple areas, categorized by improvement status. Conclusion Patients with symptoms of gastroparesis have multiple abnormalities, including systemic inflammation and disordered hormonal status. GES affects many of these abnormalities. We conclude electrical stimulation improves symptoms and physiology with (a) an early and sustained anti‐emetic effect; (b) an early and durable gastric prokinetic effect in delayed emptying patients; (c) an early anti‐arrhythmic effect that continues over time; (d) a late autonomic effect; (e) a late hormonal effect; (f) an early anti‐inflammatory effect that persists; and (g) an early and sustained improvement in health‐related quality of life. This study is registered with Clinicaltrials.gov under study # NCT03178370 (https://clinicaltrials.gov/ct2/show/NCT03178370).