Tu1210 Long Term Symptom Outcome After an Evidence Based Medicine Trial of Gastric Electrical Stimulation

Abstract

Background: We previously published (GIE 2011; 74: 496-503) an evidence based medicine study (CTRN 00432835) designed to evaluate the capacity of a 72 hour course of temporary mucosal gastric electrical stimulation (GES) to reduce nausea and vomiting, as well as other symptoms associated with the syndrome of gastroparesis. Following this study, we examined the outcomes data available from our long term clinical care of patients enrolled in the original trial subsequently implanted with permanent GES devices. Methods: Of the 58 patients in the original cross-over trial, 38 were approved by insurers and returned for permanent GES. The mean patient age was 46 years, 78% were female, 68% white, with 30% diabetic and 70% non-diabetic status. Average follow-up time in our clinical records was 4.1 years, with a maximum follow-up of 5.5 years (61% returned for 6-month followup, 71% for 12-month follow-up, and 63% for follow-up between 2.2 and 5.5 years after permanent stimulator placement). We employed a linear mixed model (random intercept), empirical Bayes approach to use the full longitudinal outcome trajectories in estimating patient-specific average long-term symptom levels after permanent placement. We then examined relationships between patient-specific final results with temporary stimulation (ON phase) during the trial and patient-specific, average long-term symptom levels. Results: Positive relationships between short-term and long-term outcomes existed, with significant associations for the Nausea and Total Symptom Score measures. We noted that 76% of the patients had no vomiting (Final Temp GES vomiting score=0) after 72 hours of temp GES, which, though a positive result from the original trial, interferes with our ability to determine associations with long-term outcomes due to minimal variation in the predictor of Vomiting (x-axis). For each unit increase in final temporary GES symptom Nausea, long-term Nausea outcomes showed associated increases of 0.3 units, 95% CI (0.02, 0.32) p=0.030. TSS showed similar significant associations between short and long-term outcomes, with a positive association of 2.1 units, (0.1, 4.1) p=0.045 (Figure 1). Gastric emptying tests (GET) for the whole group of patients changed little with temporary stimulation but did improve with long term GES, although the results were not statistically significant (Table 1). Conclusion: Long term follow up of a temporary double masked trial of endoscopic GES shows good correlation with the original symptoms improvements. We conclude that a trial of temporary GES can predict long term permanent GES outcome in patients with the symptoms of gastroparesis. Gastric motility measures pre and post treatment with GES: (N=37)