Predictive Factors for Clinical Improvement with Enterra Gastric Electric Stimulation Treatment for Refractory Gastroparesis

The objectives of this study were to determine the clinical response to Enterra gastric electric stimulation (GES) in patients with refractory gastroparesis and to determine factors associated with a favorable response. Methods This study was conducted in patients undergoing Enterra GES for refractory gastroparesis. Symptoms were scored before and after GES implantation using the Gastroparesis Cardinal Symptom Index (GCSI) with additional questions about abdominal pain and global clinical response. Results During an 18-month period, 29 patients underwent GES implantation. Follow-up data were available for 28 patients, with average follow-up of 148 days. At follow-up, 14 of 28 patients felt improved, 8 remained the same, and 6 worsened. The overall GCSI significantly decreased with improvement in the nausea/vomiting subscore and the post-prandial subscore, but no improvement in the bloating subscore or abdominal pain. The decrease in GCSI was greater for diabetic patients than idiopathic patients. Patients with main symptom of nausea/vomiting had a greater improvement than patients with the main symptom of abdominal pain. Patients taking narcotic analgesics at the time of implant had a poorer response compared to patients who were not. Conclusions GES resulted in clinical improvement in 50% of patients with refractory gastroparesis. Three clinical parameters were associated with a favorable clinical response: (1) diabetic rather than idiopathic gastroparesis, (2) nausea/vomiting rather than abdominal pain as the primary symptom, and (3) independence from narcotic analgesics prior to stimulator implantation. Knowledge of these three factors may allow improved patient selection for GES.