Gastric Electrical Stimulation

Gastric electrical stimulation (GES) uses a device implanted in the abdomen to send mild electrical pulses to the nerves and smooth muscle of the lower stomach. This helps decrease nausea and vomiting in some patients with gastroparesis.

Gastroparesis affects the nerves and muscles of the stomach, delaying the emptying of food from the stomach into the small intestine. Several different conditions can cause it, including diabetes and nervous system disorders, although in many cases the cause isn't known. GES is used to treat patients with gastroparesis due to diabetes or unknown causes only, and only in patients whose symptoms can't be controlled by medication.

The UCSF Intestinal Rehabilitation and Transplant Program began treating patients with GES in 2006, and is one of the few medical centers in Northern California to offer this treatment.

Currently the only GES device used in the U.S. is the Enterra Therapy System, which is approved by the Food and Drug Administration (FDA) under a humanitarian device exemption. These exemptions allow companies to market products for rare conditions — conditions that affect fewer than 4,000 people a year nationally — when there are no similar treatments available. If you are found to be a good candidate for GES, our team will work with your insurance company to get prior authorization for implantation of the device.

The Procedure

The implantation of the device is a one- to two-hour surgery requiring general anesthesia. In many cases the surgeon can use minimally invasive methods — making a small incision and using a viewing tube called a laparascope to guide the procedure — to avoid the need for open abdominal surgery.

The pocket watch-sized device, called a neurostimulator is surgically implanted in the right side of the abdomen. Two insulated wires are implanted into the muscle wall of the stomach then routed under your skin to the neurostimulator and connected. Once the device is activated, the wires will transmit low-energy electrical pulses to the stomach.

Most patients are discharged from the hospital one to five days after the surgery. Patients will need to come in for several follow-up appointments.

The device can be activated and programmed externally by your doctor using a handheld programmer. Your doctor may adjust the frequency and energy of the pulses to improve your results. Most patients don't feel the electrical pulses.

The relief of symptoms varies from patient to patient. One study found that one year after the implant, the median number of vomiting episodes fell by 63 percent in people with gastroparesis due to diabetes, and 83 percent in those with an unknown cause of gastroparesis. Improvement in symptoms can happen quickly or it may take months.

The device's battery lasts from five to 10 years. When the battery runs out you will need another surgery to replace the device.

Who May Benefit

GES may be appropriate if you:

  • Have diagnosed gastroparesis caused by diabetes or an unknown cause
  • Have chronic nausea, vomiting or both
  • Haven't responded to medication or don't tolerate your medications
  • Are healthy enough to undergo surgery

Please keep in mind that GES can decrease symptoms, but it isn't a cure for gastroparesis. Most patients will still need to follow a special diet and take medication to control their symptoms.


Reviewed by health care specialists at UCSF Medical Center.

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