, Volume 14, Issue 1 Supplement, pp S40-S48
Date: 13 Feb 2014

“What are the Yanks Doing?” The U.S. Experience with Implantable Gastric Stimulation (IGS) for the Treatment of Obesity — Update on the Ongoing Clinical Trials

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access



The prevalence of obesity is growing worldwide. Medical therapies are often ineffective, and surgical treatments have significant risk. IGS® offers a novel approach to weight loss that was found to be safe and effective in European trials. In the U.S., 2 consecutive trials have been undertaken.


In 2000, a multicenter, prospective, randomized, placebo-controlled trial involving 103 morbidly obese patients (U.S. O-01) was undertaken. In 2002, a prospective, open label trial involving 30 morbidly obese patients was initiated (DIGEST). Patients were followed for complications, postoperative untoward events, and weight loss.


In O-01, there were no significant perioperative complications. However, 20 patients were found to have had lead dislodgements. At 7 months, there was no significant difference in weight loss between the activated and non-activated groups. After 29 months, loss of excess weight (EWL) approached 20%. With DIGEST, there was 1 operative complication (a lost needle retrieved surgically). There were no untoward events or known lead dislodgements. EWL was 23% after only 16 months follow-up. With the introduction of a preoperative screening algorithm, almost 40% EWL was achieved for selected patients in both trials.


In the U.S., the IGS system for the treatment of obesity has been shown to be safe. Technical improvements and better patient selection resulted in improved weight loss. The preliminary results of these trials suggest that IGS may be a suitable surgical option for selected patients.