Authors' objectives: The aim of this paper is to present the current evidence on the efficacy/effectiveness, safety, and efficiency of GES (Enterra therapy system) used for the treatment of patients with severe gastroparesis (GP).

Authors' results and conclusions: One two-month, multicentre, crossover, blinded, randomized, placebo-controlled study; one comparative prospective study that compared GES therapy with medication treatment; and eight case series met the inclusion criteria. Four of 10 studies reported results from patients who were previously presented in past publications. The studies were generally of poor methodological design and average quality. Results on long-term follow-up were not available from all patients initially included in the studies. Overall, the results from studies that reported on patients who were not part of another published study indicated symptomatic improvement after GES. In the randomized crossover study with results measured at one month of follow-up for stimulation ON and OFF with the GES device, the weekly vomiting frequency and total symptom score (TSS) for severity measured separately for diabetic and idiopathic patients showed an improvement compared with baseline values. The differences between the stimulation ON and OFF period were not statistically significant. The case-series studies reported outcome results mainly at 6 months and 12 months of follow-up. In four studies, the reduction in the frequency and/or severity of vomiting and/or nausea was found to be statistically significant at 6 and 12 months of follow-up. Statistically significant improvement of gastrointestinal TSS of severity and/or frequency was indicated in two studies at 6 and 12 months of follow-up. Improvement of nutritional status measured by patient weight was found to be statistically significant in two studies at 6 and 12 months and in one study at 20 months of follow-up. Statistically significant improvement of quality of life was reported in two studies at 6 and 12 months of follow-up. A reduction in supplementary enteral and parenteral feeding (four studies) and a reduction in reliance on drugs to alleviate symptoms (three studies) were also noted, statistical significance not having been reported, at 12 months of follow-up. However, these improvements were not associated with improvement of gastric emptying. GES apparently does not cause the muscle of the stomach to contract and only has a modest improvement in gastric emptying. The mechanism of action of the GES system is still unclear. Overall, these results need to be cautiously interpreted, as many authors noted that the effects of benefits may be placebo attributed. The use of GES, as with any implanted device, is not without risk. The most common adverse events reported were infection at the pocket site of the impulse generator or erosion, either of which required the removal of the system, and electrode dislodgement, which required reintervention. There is insufficient information to determine the efficiency of GES. In Canada, the device itself costs approximately Cdn $10,685.

Authors' recommendations: Candidates for GES treatment are a select group of patients aged 18 to 70 years who do not respond to drug therapies and sometimes have severe associated comorbidities (depletion of electrolytes, malnutrition, and a depressed immune system). GES is used more often for symptom control rather than treatment of the motility disorder. The current evidence, based on an average of 12 months of follow-up on the safety and efficacy of GES for patients with idiopathic GP or GP associated with diabetes or surgery who tolerated the implanted device, is not adequate to support the routine use of this procedure. It would, however, be considered a last-resort treatment after all conventional treatment regimes had failed to control symptoms of nausea and vomiting. The research on GES for GP associated with other conditions has yet to be done. Because of possible risks associated with the implantation of this device, the implantation should be provided by trained professionals and the use of the device should be restricted to those patients who have severe symptoms and are refractory to another less invasive and risky approach such as drug therapy and diet. A continuous follow-up of the patients is necessary to identify possible adverse events and effects related to the condition and to treatment, as well as to assess the costs and quality of life experienced by patients. Controlled studies are ongoing or have been planned and after this research is published, this technology should be reviewed again to determine if the cumulative research adds to the knowledge of efficacy/effectiveness.

Authors' methods: Review

Project Status: Completed

Year Published: 2006

URL for published report: http://www.ihe.ca/advanced-search/gastric-electrical-stimulation-enterratm-therapy-system-for-the-treatment-of-gastroparesis

URL for additional information: http://www.health.alberta.ca/initiatives/health-evidence-reviews-list.html

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Canada

Organisation Name: Institute of Health Economics

Contact Address: 1200, 10405 Jasper Avenue, Edmonton, Alberta, Canada, T5J 3N4. Tel: +1 780 448 4881; Fax: +1 780 448 0018;

Contact Name: djuzwishin@ihe.ca

Contact Email: djuzwishin@ihe.ca

Copyright: <p>Alberta Heritage Foundation for Medical Research (AHFMR)</p>