Worldwide Anti-Vomiting Electrical Stimulation Study

In a multicenter clinical study1 (WAVESS – Worldwide Anti-Vomiting Electrical Stimulation Study), a majority of patients experienced improvements in weekly vomiting episodes after receiving an EnterraTM implant compared to the number of vomiting episodes before GES. The Enterra Therapy Clinical Summary contains details of the study.

Thirty-three (33) patients with chronic gastroparesis* were enrolled in WAVESS (17 of diabetic origin and 16 of idiopathic origin). Symptoms were compared between baseline and 6 and 12 months. 

Graph showing WAVESS: Median Weekly Vomiting (episodes/week)

At both follow-ups and for both patient groups, the median weekly vomiting episodes were significantly reduced:

  • At 6 months after implant, the median vomiting frequency declined 80% for the diabetic group and 88% for the idiopathic group (n = 27)
  • At 12 months after implant, the median vomiting frequency declined 63% for the diabetic group and 83% for the idiopathic group (n = 24)

Evaluation of secondary endpoints showed many patients experienced improvement in2:

  • Quality of life (73%)
  • Ability to tolerate solid meals (73%)

Also, there was a trend in improvement for gastric retention, subjective symptoms, and hypoglycemic attacks.2

Common Adverse Events

Common system-related adverse events during the WAVESS study included device infections, lead penetration, irritation/inflammation over the neurostimulator site, pain at neurostimulator site, and mechanical or electrical problems with device.


Humanitarian Device: The effectiveness of this device for this use has not been demonstrated. Learn more about HDE.


Abell T, McCallum R, Hocking M, et al. Gastric electrical stimulation for medically refractory gastroparesis. Gastroenterology. 2003; 125:421-28.


Medtronic Enterra Therapy Clinical Summary (2014).