Neuroenteric Stimulation for Gastroparesis

Gastroparesis (GP) is a syndrome characterized by delayed gastric emptying in association with symptoms of epigastric pain, nausea, and vomiting in the absence of mechanical obstruction. The prevalence of gastroparesis has been estimated at 24 per 100,000, with women more commonly affected than men. Diabetes appears to be the underlying cause in approximately 25 % of patients, while connective tissue disorders, autoimmune disorders, prior gastric surgery, ischemia, and medications make up a smaller percentage of the remaining identifiable causes. However, the largest group of GP patients falls into the idiopathic category (~50 %); many of these patients likely develop GP as a result of a prior viral infection. Symptoms of gastroparesis develop due to a number of different pathophysiologic processes, including disorders of fundic accommodation, antroduodenal dyscoordination, a weak antral pump, gastric dysrhythmias, abnormal duodenal feedback, and enhanced visceral sensation. Once the diagnosis of GP is made, the clinician has a number of different treatment options. For patients with mild to moderate symptoms, dietary modifications in conjunction with or without prokinetics and antiemetics are often all that is required. However, many patients with severe symptoms who fail to respond to standard therapy may benefit from neuroenteric stimulation (gastric electrical stimulation). This monograph will review the role of the neuroenteric stimulator therapy for gastroparesis, discuss possible mechanisms of action of neuroenteric stimulation, review data from recently published studies on its efficacy, and discuss patient selection and adverse events.