Laparoscopic Insertion of Gastric Electrodes for Electrical Stimulation

Gastric Electrical Stimulation for Gastroparesis and Chronic Unexplained Nausea and Vomiting

OPINION STATEMENT

Gastroparesis is a heterogeneous clinical syndrome. Some patients have debilitating vomiting, weight loss, and dehydration, while others have effortless regurgitation of undigested foods or postprandial distress suggestive of functional dyspepsia. Gastric electrical stimulation (GES) has been proposed as an effective treatment option for patients with gastroparesis refractory to medical therapy. Evidence suggests that the clinically available device, a low-energy high-frequency GES, activates the vagal afferent pathways to influence the central control mechanisms for nausea and vomiting. Myoelectrical effects of the stomach are also involved. The results of randomized controlled trials (RCTs) for adults with diabetic and idiopathic gastroparesis are conflicting. There are no RCTs in adults with chronic unexplained nausea and vomiting (CUNV) with normal gastric emptying or in children with gastroparesis. However, there is increasing evidence from large unblinded studies showing the long-term efficacy in selected adults with gastroparesis. Selection criteria should be based on three categories: (a) underlying etiology, (b) clinical presentation and predominant symptoms, and (c) potential risk for complication. Significant abdominal pain, daily opiate use, and idiopathic gastroparesis are identified as negative predictors of success. Temporary GES has been utilized to identify patients who may benefit from surgical GES, but this strategy has yet to be proven in controlled studies. Objectives for this review are to highlight the mechanisms of action for GES, to look at the evidence for clinical efficacy, and to select patients who are likely to benefit.

Follow-up after gastric electrical stimulation for gastroparesis

BACKGROUND

Gastric electrical stimulation (GES) is used to treat medically refractory gastroparesis. However, there are few large series with outcomes beyond 12 months. This study reports surgical outcomes of GES for patients up to 8 years receiving treatment from a single institution.

STUDY DESIGN

A prospective database was reviewed from 2003 to 2013 for patients undergoing GES. Baseline patient characteristics were recorded, including age, sex, cause of gastroparesis, gastric emptying, and Hgb A1C. Outcomes variables included nutrition supplementation, additional operations, 30-day morbidity, and mortality. Pre- and postoperative pain and function scores are analyzed over time using generalized estimating equations. Patient outcomes in terms of reoperation rates and types of operations are also reviewed.

RESULTS

Seventy-nine patients underwent GES with a mean ± SD age of 43 ± 11 years and a BMI of 27 ± 8 kg/m(2). Symptom scores were available for 60 patients: 60 patients at baseline, 52 patients at 1 year, 14 patients during years 2 to 3, and 18 patients during years 4 to 8. Symptom scores decreased considerably in all categories. At 1-year follow-up, 44% and 31% of patients had at least a 25% reduction in symptom distress for functional and pain symptoms, respectively. Preoperatively, 9 patients required nutrition supplementation. After implantation, 34 (43%) patients underwent additional operations, with a mean of 2.15 operations per patient. Generator-related causes were the most common indication for reoperation, including battery exchanges and relocation. Other operations included 8 gastrectomies and 7 median arcuate ligament releases. Postoperatively, 4 patients required supplemental nutrition. There were no 30-day mortalities, but 11 patients died during the study period.

CONCLUSIONS

Gastric electrical stimulation was significantly associated with reductions in both functional and pain-related symptoms of gastroparesis. Patients who undergo GES have a high likelihood of additional surgery.

Gastric electrical stimulation for gastroparesis

BACKGROUND

Recently, gastric electrical stimulation (GES) has been used to treat gastroparesis. This study analyzes a cohort of gastroparetic patients after GES.

STUDY DESIGN

All patients undergoing GES from October 2003 to July 2007 were included. Pre- and postoperative assessments were performed for frequency and severity of gastrointestinal symptoms and gastric retention. The values were compared using a paired t-test for patients at 6 and 12 months. Statistical significance was defined as p < 0.05.

RESULTS

Fifty gastroparetic patients were enrolled (20 diabetic, 25 idiopathic, 2 postsurgical, and 3 connective tissue disorder patients). All patients underwent laparoscopic implantation with GES (Medtronic, Inc). Median followup was 28 months (range 3 to 51 months). Thirty-five patients were available for followup at 6 months, and 30 patients were available at 12 months. The total symptom severity score (19.05+/-8.04) decreased significantly at 6 months (12.92+/-7.41, p < 0.001) and 12 months (14.05+/-8.28, p < 0.01). Similarly, total frequency score (20.39+/-8.08) decreased significantly at 6 months (15.01+/-7.37, p < 0.01) and 12 months (15.71+/-7.40, p < 0.05). At 12 months (n=27), gastric retention at 2 hours was decreased significantly from 66% +/- 21% to 50% +/- 22% (p < 0.04) and normalized in 11 of 27 patients. The severity of symptoms was reduced in all patients with normal gastric retention postoperatively. Finally, gastric retention at 4 hours was reduced by 14%, but the difference was not significant.

CONCLUSIONS

Gastroparetic symptoms at 6 months were improved and sustained at 12 months after GES. Gastric emptying at 2 hours was reduced significantly after GES. Longterm followup of this cohort is required to confirm the short-term effects of GES.