Long-term follow-up of gastric stimulation for obesity: the Mestre 8-year experience

10 years experience with gastric stimulation demonstrates promise, in particular because weight loss is achieved and maintained without drugs or side-effects. We report on a total of 65 patients who have received an Implantable Gastric Stimulator (IGS(R)) since 1995.

65 patients have received an IGS and were monitored for weight loss as well as co-morbidities. Gastroesophageal Reflux Disease (GERD) was assessed by endoscopy and symptoms were evaluated. An acute Holter study was performed on 4 patients pre-implant, post-implant, and post-activation of the IGS. Oral glucose tolerance test (OGTT) using a 76-g bolus of oral dextrose was done before device implantation and after-activation. Gastric emptying was tested on 19 of the patients using Tc99, both pre-implant and 6 months post-implant. Resting Energy Expenditure (REE) was studied in 15 patients using indirect calorimetry at 3 different points in time: pre-activation, 6 months post-implant, and 12 months post-implant. Blood pressure was measured using an electronic wrist device to overcome potential artifacts due to arm fat.

IGS patients lost significant weight with no side-effects and experienced significant and rapid improvements in blood pressure. Almost all of the GERD patients reported symptomatic relief during gastric pacing. OGTT demonstrated improved response to insulin at 7 months post-stimulation. The gastric emptying and REE tests were less conclusive, to a great extent because of the small sub-population of patients.

While the exact mechanisms of gastric stimulation remain incompletely understood, it appears that the implantation of an IGS is associated with weight loss, an improvement (decrease) in blood pressure in hypertensive patients, and a reduction or elimination of symptoms in those who had GERD. This promising weight loss therapy warrants further study, in particular because of its intriguing results with co-morbidities.