Gastric pacing (gastric electrical stimulation) for the treatment of obesity

Findings by SBU Alert

Version: 1

Technology and target group

Gastric pacing is a new method to treat obesity by electrical stimulation of the stomach by means of an implanted electrode. The pulse generator, which looks like an ordinary cardiac pacemaker, is implanted subcutaneously. The pacemaker electrode is surgically implanted in the stomach wall. The procedure, which is performed laparoscopically (keyhole surgery), is suitable for either out-patients or in-patients (requiring only a short period of hospitalization in the latter case). So far, the method has been used primarily on obesity patients who are currently eligible for surgery in Sweden, i.e., those with a body weight index (BMI) above 40 kg/m² – or 35 for those with a complicating disease. However, gastric pacing is marketed in other countries for patients with a BMI of 30 and over. The reason that we have assessed this kind of treatment is that obesity is a major, widespread health problem, so that new methods are of great potential significance.

Patient benefit

A handful of small, open non-controlled trials have examined patient benefit. The average body weight of the patients decreased, though to a varying degree, in each of the trials. No results of a randomized controlled trial have yet been published. The preliminary findings of a Swedish study, which included 10 patients, indicated that weight loss after 6 months was the same regardless of whether or not the pulse generator had been activated.

The most frequent problem during the trials arose when an electrode dislodged from the stomach wall.

Gastric pacing is associated with the risk of perforation of the gastric mucosa. One trial reported the complication in 10 percent of the procedures, one in 15 percent and one in 32 percent. There is considerable risk of serious infection unless the perforation is detected during surgery. No deaths have been reported in connection with this treatment.

Economic aspects

No health economic assessments have been identified. In addition to the surgery itself, the Transcend Implantable Gastric Stimulator system (IGST), which is presently in use, costs between 80 000 and 95 000 Swedish kronor (SEK). The batteries for the current models have an estimated lifetime of two to four years.

Scientific evidence

There is insufficient scientific evidence on the short-term patient benefit of gastric pacing (Evidence grade 4)*. There is no scientific evidence on the long-term patient benefit of gastric pacing (Evidence grade 4)*. No scientific evidence is available on the cost effectiveness of the treatment (Evidence grade 4)*.

Gastric pacing is still an experimental method and should be used only in scientific studies that have been approved by a research ethics committee. Trials that include adequate control groups are very much needed.

*Grading of the level of scientific evidence for conclusions. The grading scale includes four levels;
Evidence grade 1 = strong scientific evidence,
Evidence grade 2 = moderately strong scientific evidence,
Evidence grade 3 = limited scientific evidence,
Evidence grade 4 = insufficient scientific evidence.

This summary is based on a report prepared at SBU in collaboration with Assoc. Prof. Ingmar Näslund, Örebro University Hospital, Örebro. It has been reviewed by Assoc. Prof. Jarl S:son Torgerson, Sahlgrenska University Hospital, Göteborg.

The complete report is available only in Swedish.

SBU Alert is a service provided by SBU in collaboration with the Medical Products Agency, the National Board of Health and Welfare, and the Federation of Swedish County Councils.

References

1. Aigner F, Weiss H, de Gheldere G, Favretti F, Gaggiotti G, Himpens J et al. A prospective survey on the Transcend Implantable Gastric Stimulator (IGS): A preliminary report. Obesity Journal 2003;13:542 (Abstract).
2. Cigaina V. Gastric pacing as therapy for morbid obesity: preliminary results. Obes Surg 2002;12 Suppl 1:12S-16S.
3. Cigaina V, D´Argent J, Belachew M, Melissas J, Miller K, Favretti F et al. Treatment of obesity with the Transcend Implantable Gastric Stimulator: Multi-center study. Obesity Journal 2003;13:548 (Abstract).
4. D´Argent J. Gastric electrical stimulation as therapy of morbid obesity: preliminary results from the French study. Obes Surg 2002;12 Suppl 1:21S-25S.
5. De Luca M, Segato G, Busetto A, Ceoloni A, Magon A, Enzi G et al. Preliminary experience with the Transcend Implantable Gastric Stimulator (IGS). Obesity Journal 2003;13:552 (Abstract).
6. Klockhoff Hampus, Ågren Göran, Näslund Ingmar: abstract ECO/IFSO Prague May 2004., e-mail: ingmar.naslund@orebroll.se.
7. SBU Rapport nr 160. Fetma - problem och åtgärder: Statens beredning för medicinsk utvärdering, Stockholm; 2002.
8. Shikora S. Operative technique modification improves lead security for Transcend Implantable Gastric Stimulator (IGS). Obes Surg 2002;12:457 (Abstract).
9. Wolff S, Pross M, Knippig C, Malfertheiner P, Lippert H. Gastric pacing. Eine neue Methode in der Adipositaschirurgie. Chirurg 2002;73(7):700-3.