Benefits and risks

Information for the public

When NICE looked at the evidence, it decided that the procedure is safe enough and works well enough for use in the NHS. The 8 studies that NICE looked at involved a total of 1765 patients.

Generally, they showed the following benefits:

Symptoms generally improved (including weekly vomiting frequency) in patients with diabetes, in those with gastroparesis of an unknown cause, and in those who had abdominal surgery, and patients spent less time in hospital after 1 year.
Stomach emptying was improved after 4 hours in people with diabetes and gastroparesis without an obvious cause, but not in people who had had abdominal surgery.
Patients' weight didn't change.
Fewer patients needed nutritional support after having the procedure.
Quality of life improved.

The studies showed that the risks of gastrointestinal stimulation included:

A hole in the gut occurred after vomiting in 1 patient out of 17, 2 months after the procedure.
The device needed to be removed in about 1 in 10 patients, for reasons including infection, blockage in the bowel, the device or its wires moving, the device wearing away through the skin, and symptoms not improving.
The battery failed and the device had to be replaced in about 1 in 50 patients.
Wires from the device wore away some tissue around them in fewer than 1 in 100 patients.
The treatment didn't work in about 1 in 4 patients. Reasons included symptoms not improving, and the, device malfunctioning or stopping working.

In one study, 2 out of 72 patients died after having the procedure, because of blood supply to the bowel being cut off, and heart failure.

NICE was also told about some other possible risks: pain where the device is inserted, and a feeling of pins and needles when the device is turned on.

If you want to know more about the studies see the guidance. Ask your health professional to explain anything you don't understand.