Gastric Neurostimulators and Treatment of Gastroparesis

What is Gastroparesis ?

The most common symptoms of gastroparesis – chronic nausea and vomiting – can make everyday life a challenge. 

DEFINITION

Gastroparesis is a stomach disorder in which food is digested more slowly than normal. In a healthy digestive system, strong muscular contractions move food from the stomach through the digestive tract. With gastroparesis, however, the stomach muscles work poorly (or not at all), thus preventing the stomach from emptying properly. The patient has a sensation of bloating and abdominal distension. For some people, this condition results in serious nausea and vomiting that cannot be adequately controlled with standard medications.

CAUSES

Gastroparesis has several different causes, including type 1 diabetes and type 2 diabetes, and in many cases the cause is unknown (idiopathic).

SYMPTOMS

Typical symptoms include:

• Nausea
• Vomiting
• Abdominal bloating
• Abdominal pain
• Feelings of fullness after only a few bites of food
• Heartburn or gastroesophageal reflux disease (GERD)
• Changes in blood sugar levels
• Lack of appetite
• Excessive weight loss

IMPACT OF GASTROPARESIS

The impact of gastroparesis on physical well-being can be devastating. It can cause chronic nausea and vomiting and lead to malnutrition and inadequate blood sugar levels. Living with gastroparesis also affects emotional well-being – the constant discomfort of chronic nausea and vomiting can affect school and work performance, family and personal relationships, and social activities.

DIAGNOSIS

Diagnosis is based on a complete medical history, physical examination, and tests that may include:

• Upper gastrointestinal endoscopy (EGD)
• Gastric emptying test (GET)
• Gastroduodenal manometry
• Electrogastrography (EGG)

Ask your doctor about other medical conditions or medications that may cause symptoms similar to those of gastroparesis.

GASTRIC NEUROSTIMULATOR

A small medical device called a neurostimulator is implanted under the skin, usually in the lower abdominal region. Two insulated wires called leads are implanted in the stomach wall muscle and then connected to the neurostimulator. The procedure is performed under general anesthesia.

The neurostimulator sends mild electrical pulses through the leads to stimulate the smooth muscles of the lower stomach. This may help to control the chronic nausea and vomiting associated with gastroparesis* caused by diabetes or an unknown origin in patients aged 18 to 70 years.

After the device is implanted, the doctor uses a handheld, external programmer to adjust the neurostimulator and customize the stimulation. Stimulation can be adjusted without surgery. The stimulation can be turned off by the doctor at any time if the person experiences any intolerable side effects.

Refer to Probable Benefits and Risks for risk and side effect details regarding implantation of an Enterra™ system.

HUMANITARIAN DEVICE

A humanitarian device is a medical device specially designated by the US Food and Drug Administration (FDA) for use in the treatment of a rare medical condition (fewer than 8000 new cases per year in the United States). The FDA requires that any physician who wishes to use the device to treat a patient must first obtain approval from the hospital’s institutional review board. The Medtronic Enterra Therapy system was designated as a device for humanitarian use by the FDA in 1999.

After Enterra Therapy was designated for humanitarian use, Medtronic submitted a Humanitarian Device Exemption (HDE) application to the FDA. This type of application is not required to contain the results of scientifically valid clinical investigations demonstrating that the device is effective for its intended purpose. However, it must contain sufficient information for the FDA to determine that the device does not pose an unreasonable or significant risk of illness or injury and that the probable benefit to health outweighs the risk of injury or illness from its use, taking into account the probable risks and benefits of currently available devices or alternative forms of treatment. Also, the applicant must demonstrate that no comparable devices are available to treat or diagnose the disease or condition, and that the applicant could not otherwise bring the device to market. Once the FDA approved the Humanitarian Device Exemption in 2000, Medtronic was able to manufacture and distribute Enterra Therapy in the United States.

Enterra II Neurostimulator

Gastric Electrical Stimulation

OVERVIEW

The EnterraTM II gastric neurostimulator is a programmable device that generates mild electrical pulses for gastric electrical stimulation to treat chronic, intractable nausea and vomiting due to gastroparesis.*

This small, battery-powered gastric neurostimulator is implanted beneath the skin in the lower abdominal region. The neurostimulator generates controlled electrical pulses delivered by leads to the antrum portion of the stomach muscle wall. After implant, the clinician optimizes therapy for the patient with a clinician programmer.

INDICATIONS

The Medtronic Enterra Therapy System for gastric electrical stimulation (GES) is indicated for use in the treatment of chronic, intractable (drug refractory) nausea and vomiting secondary to gastroparesis of diabetic or idiopathic etiology in patients aged 18 to 70 years.

*Humanitarian Device: The Enterra Therapy system for gastric electrical stimulation is authorized by Federal law for use in treatment of chronic intractable (drug refractory) nausea and vomiting secondary to gastroparesis of diabetic or idiopathic etiology. The effectiveness of this device for this use has not been demonstrated. What does this mean?