Enterra® gastric electrical stimulation for idiopathic gastroparesis: Results from a multicenter randomized study

INTRODUCTION: Chronic refractory nausea and vomiting secondary to diabetic or idiopathic gastroparesis (IGp) profoundly impairs quality of life (QoL). Enterra® Therapy is available to treat this condition under a Humanitarian Device Exemption. This was a prospective, multicenter, double-blind, randomized, controlled, crossover study designed to evaluate the efficacy of Enterra Therapy. This abstract reports on IGp; results from diabetic gastroparesis were previously reported (DDW 2009). METHODS: Following a 28-day baseline period, drug refractory IGp patients were implanted with an Enterra gastric stimulator. After surgery, patients had the stimulator turned ON for 6 weeks followed by double-blind randomization to consecutive 3-month crossover periods with the device either ON or OFF. After the crossover, patients were programmed ON and followed in an unblinded fashion until 12 months post-implant. A 5-point scale was used for assessing IGp symptoms and SF-36 was used for QoL. RESULTS: Thirty-two patients (mean age 39, 81% F, 7.7 years of IGp) were implanted. During the initial 6-week unblinded ON period (n=25), weekly vomiting frequency (WVF) reduced significantly from 17.5 episodes at baseline to 5.5 (median reduction= 61%, p<0.001). There was a non-significant reduction in WVF during the crossover period (n=20) with a median of 9.8 episodes during the OFF period versus 6.4 during the ON period (median reduction=17.3%; p>0.10). However, 15 of 20 subjects preferred the ON period compared to the OFF period (p=0.021). At 1 year post implant (n=18), WVF remained significantly lower than baseline (median reduction=87%, p<0.001) accompanied by a significant decrease in nausea, early satiety, bloating, postprandial fullness, and epigastric pain. Gastric emptying (GE) at 2h improved with a median retention of 49.0% at 1 year versus 63.5% at baseline (p=0.016) but improvements at 4h were not statistically significant. At 1 year, SF-36 scores significantly improved compared to baseline (Physical p<0.05; Mental p<0.001). CONCLUSIONS: In refractory IGp patients, Enterra Gastric Electric Stimulation resulted in a rapid, significant, and sustained decrease, for 1 year, in vomiting and gastroparetic symptoms, improved GE, and improved QoL. Patients preferred the ON versus the OFF period during the double-blind period; however, the decrease in WVF was not significant. We speculate that the initial 6-week stimulation period had a carryover effect into the double blind period leading to the lack of further reduction during the blinded ON period. Although these results support the efficacy of Enterra Therapy for idiopathic gastroparesis, further research is needed.