Gastroparesis

What is gastroparesis?

Gastroparesis is a condition where symptoms occur and the stomach empties too slowly. No blockage is evident. The delayed emptying is confirmed by a test.

How common is gastroparesis?

While the incidence and prevalence of gastroparesis are not well-defined, it is estimated to affect up to 5 million individuals in the United States.[1]

What are the symptoms of gastroparesis?

Symptoms usually occur during and after eating a meal. Typical symptoms include:

  • Nausea and/or vomiting
  • Retching (dry heaves)
  • Stomach fullness after a normal sized meal
  • Early fullness (satiety) – unable to finish a meal

There may also be bloating, heartburn, and stomach discomfort or pain. Decreased appetite may result in weight loss.

What causes gastroparesis?

Most often in people with gastroparesis, the cause is unknown and is termed “idiopathic.” Symptoms may begin following a virus infection. Other possible causes include diabetes, surgeries, some medications, and other illnesses.

Diabetes
Gastroparesis may occur as a complication of other conditions. Long-standing diabetes is the most common known cause of gastroparesis, although only a small percentage of people with diabetes develop gastroparesis. The cause of symptoms is probably due to damage to nerves that supply the stomach.

The vagus nerve transmits impulses to the stomach and intestines. Injury to the vagus nerve can impair gastric emptying.

Surgeries
Gastroparesis can also result as a complication from some surgical procedures. Most often these include nerve damage following esophageal or upper abdominal surgeries.

Medications
Less frequently, gastroparesis is seen to occur after the use of certain medications. Some medications can impair motility. Examples include:

  • narcotic pain relievers,
  • anticholinergic/antispasmodic agents,
  • calcium channel blockers,
  • some antidepressants, and
  • some medications for diabetes.

Other Illnesses
Sometimes gastroparesis is seen in association with other illnesses. Systemic illnesses, neurologic diseases, or connective disorders, such as multiple sclerosis, Parkinson’s disease, cerebral palsy, systemic lupus, and scleroderma are associated with gastroparesis. The cause and effect is unclear.

In a small number of people, gastroparesis symptoms appear to develop after onset of an apparent viral infection (post-infectious or postviral gastroparesis). The symptoms usually resolve or improve over time.

Much remains to be learned about what causes gastroparesis. In both idiopathic and diabetic gastroparesis a great deal of interest is being paid to changes in the cells which help control muscular contractions (motility) in the stomach. These are known as the interstitial cells of Cajal (ICCs). These cells probably represent the essential pacemakers of the entire gastrointestinal (GI) tract. In addition to ICCs, scientists are looking at changes in the structure and the number of nerve cells and immune cells as possible contributors to the disease process in gastroparesis.

How do I know if I have gastroparesis?

The symptoms of gastroparesis are similar to those that occur in a number of other illnesses. When symptoms persist over time or keep coming back, it’s time to see a doctor to diagnose the problem. An accurate diagnosis is the starting point for effective treatment.

Diagnosis of gastroparesis begins with a doctor asking about symptoms and past medical and health experiences (history), and then performing a physical exam. Any medications that are being taken need to be disclosed.

Tests will likely be performed as part of the examination. These help to identify or rule out other conditions that might be causing symptoms. Tests also check for anything that may be blocking or obstructing stomach emptying. Examples of these tests include:

  • a blood test,
  • an upper endoscopy, which uses a flexible scope to look into the stomach,
  • an upper GI series that looks at the stomach on an x-ray, or
  • an ultrasound, which uses sound waves that create images to look for disease in the pancreas or gallbladder that may be causing symptoms.

If – after review of the symptoms, history, and examination – the doctor suspects gastroparesis, a test to measure how fast the stomach empties is required to confirm the diagnosis.

Slow gastric emptying alone does not correlate directly with a diagnosis of gastroparesis. (Pasricha PJ, et al. Clin Gastroenterol Hepatol. 2011 July.)

Stomach Emptying Tests

There are several different ways to measure the time it takes for food to empty from the stomach into the small intestine. These include scintigraphy, wireless motility capsule, or breath test. Your doctor will provide details of the one chosen.

Gastric Emptying Study (Scintigraphy)
The diagnostic test of choice for gastroparesis is a gastric emptying study (scintigraphy). The test is done in a hospital or specialty center.

It involves eating a bland meal of solid food that contains a small amount of radioative material so that it can be tracked inside the body. The abdomen is scanned over the next few hours to see how quickly the meal passes out of the stomach. A radiologist will interpret the study at periodic intervals after the meal.

A diagnosis of gastroparesis is confirmed when 10% or more of the meal is still in the stomach after 4 hours.

Other methods for measuring gastric emptying include a wireless motility capsule and a breath test.

Wireless Motility Capsule
The ingestible wireless motility capsule (SmartPill) is swallowed and transmits data to a small receiver that the patient carries. The data collected is interpreted by a radiologist. While taking the test, people can go about their daily routine. After a day or two, the disposable capsule is excreted naturally from the body.

Breath Test
The breath test involves eating a meal that contains a nonradioactive component that can be tracked and measured in the breath over a period of hours. The results can then be calculated to determine how quickly the stomach empties.

How is gastroparesis treated?

Treatments are aimed at managing symptoms over a long-term. This involves one or a combination of dietary and lifestyle measures, medications, and/or procedures that may include surgery.

Mild symptoms that come and go may be managed with dietary and lifestyle measures. Moderate to more severe symptoms additionally may be treated with medicines to stimulate stomach emptying and/or reduce nausea and vomiting.

Severe symptoms that are harder to treat may require added procedures to maintain nutrition and/or reduce symptoms.

Dietary and Lifestyle Measures

A nutrition specialist can help design a dietary plan to meet your needs. If you have diabetes, blood glucose levels will need to be controlled as well as possible. Blood glucose levels go up after stomach contents empty into the small intestine, and this is irregular in gastroparesis. Learn more about gastroparesis dietary and lifestyle measures.

Medications

Prokinetic (promotility) agents help the stomach empty more quickly and may improve nausea, vomiting, and bloating. Antiemetic agents are used to treat nausea and vomiting.

Medications are used to try to help reduce symptoms of gastroparesis. The drug categories commonly used are prokinetic (promotility) agents and antiemetic agents.

There is a lack of evidence-based information about what drugs work best for patients with gastroparesis. Drugs are often prescribed off-label by doctors, based on their clinical experience and how the drugs treat similar symptoms in other conditions. Only one drug, metoclopramide, is approved by the U.S. Food and Drug Administration (FDA) for the treatment of gastroparesis.

Off-label use is the permissible practice by doctors to prescribe medications for other than their FDA approved intended indications.

Prokinetic/Promotility Agents
Prokinetic, or promotility, agents directly help the stomach empty more quickly and may improve symptoms such as nausea, vomiting, and bloating.

Metoclopramide, a dopamine antagonist, has been available since 1983. It is the only FDA approved medication that improves stomach emptying. Multiple clinical trials show that it improves symptoms in about 40% of patients. Intolerable side effects are common and 20–40% of patients cannot take this drug.

The most bothersome side effect, tardive dyskinesia, is a rare but serious movement disorder that is often irreversible. The risk of developing tardive dyskinesia increases with the duration of treatment and the total cumulative dose. Treatment with metoclopramide for longer than 12 weeks should be avoided in all but rare cases where therapeutic benefit is thought to outweigh the risk of developing tardive dyskinesia. ()

Domperidone, a peripheral dopamine antagonist, is a prokinetic agent that has never been approved by the FDA. It is similar in effectiveness to metoclopramide, but has fewer side effects. It is available in Canada, Mexico, New Zealand, Japan, and Europe. In the U.S. it can be obtained through a doctor under special arrangements (). An intravenous form of domperidone was removed from the market in 1980 because of some unexpected serious heart problems (cardiac arrhythmias). An electrocardiogram (EKG), which tests electrical activity in the heart, should be done before starting this medication. Follow-up EKG is recommended in those who are taking the drug. Caution should be used in older patients or those with known cardiac disease.

Erythromycin is an antibiotic that is structurally similar to motilin, a hormone that speeds up stomach emptying. Motilin is decreased in people with diabetes. About 40% of people with diabetic gastroparesis will improve with short courses of erythromycin. However, effectiveness of erythromycin often decreases sharply after several weeks of taking the drug. Possible side effects of erythromycin include nausea, vomiting, and abdominal cramps.

Antiemetic Agents
Antiemetic agents are used to treat nausea and vomiting, which are disabling symptoms. These agents do not improve gastric emptying.

These drugs work on a range of receptors in the nervous system in the body. There are a number of these medications, which have been developed for other conditions. For gastroparesis, doctors will make recommendations based on clinical experiences and observations, and individual patient needs. Among these drugs are certain serotonin 5-HT3 receptor antagonists, antihistamines, phenothiazines, low-dose tricyclic antidepressants, and others.

Many of these drugs come in multiple formulations so that they can be taken as an oral tablet, dissolvable tablet, liquid, or intravenously (IV) as required. Possible side effects for each of these drugs should be discussed by the doctor and patient.

Procedural Treatments

Botulinum Toxin Injection
Botulinum toxin (Botox) is a nerve blocking agent. Some initial research studies in small numbers of patients showed modest improvement in gastroparesis symptoms and the rate of gastric emptying following the injections of Botox into the pylorus, the opening from the stomach into the small intestine. However, other more well-designed studies have shown no improvement in symptoms compared to placebo. It is not a generally recommended treatment for gastroparesis, based on randomized controlled trials.

Procedures –Severe symptoms sometimes result in dehydration, loss of essential minerals (electrolyte imbalances), and malnutrition requiring hospitalizations. Special treatment measures to help manage may include:

  • enteral nutrition,
  • parenteral nutrition,
  • gastric electrical stimulation, or
  • other surgical procedures.

Enteral nutrition involves the delivery of liquid food into the digestive tract through a feeding tube. It is used when oral eating does not supply adequate nutrition. Delivery into the small intestine is called a jejunostomy.

Jejunostomy (J-tube) is a surgical procedure that places a feeding tube through the abdominal wall directly into the small intestine, bypassing the stomach. In this procedure, the feeding tube delivers nutrients in a specially formulated liquid food directly into the jejunum, the part of the small intestine where most nutrients are absorbed into the body. (A temporary, nasojejunal, feeding tube should be tried first to test individual toleration of this feeding method.)

Parenteral nutrition bypasses the digestive system. It involves the delivery of fluids, electrolytes, and liquid nutrients into the bloodstream through a tube surgically placed in a vein (intravenous or IV). Parenteral nutrition is a complex therapy, used when no other treatments are working. Long-term use increases risks for infections and other complications. It may be used as a temporary treatment for gastroparesis.

Gastric electric stimulation (GES) uses a battery-operated surgically implanted device (Enterra) on the stomach to try to help reduce symptoms of nausea and vomiting in gastroparesis when other methods have failed. Low voltage pulses are too weak to excite stomach smooth muscles, but are able to excite nerves. Therapy with Enterra is FDA approved through a Humanitarian Use Device exemption. The device can be implanted laparoscopically, which helps minimize chances for complications related to surgery. Once implanted, the settings on the battery-operated device can be adjusted to determine the settings that best control symptoms.

First FDA approved in 2000, the FDA approved a second-generation device (Enterra II) in 2015. The newer device provides physicians with greater system flexibility and ease of use.

Enterra therapy is not a cure and other treatment approaches need to be continued. The device can be removed if the therapy does not work.

Other surgical procedures may sometimes be tried in patients where all other treatments fail. Gastrostomy (a tube into the stomach) venting prevents excess air and fluid from building up in the stomach and may help with severe nausea and vomiting. Pyloroplasty (surgery to widen the lower part of the stomach) or gastrojejunostomy (surgical procedure that connects the stomach to the jejunum part of the small intestine) are attempts to help the stomach empty. Gastrectomy is the surgical removal of part or the whole stomach. The effectiveness of these procedures in the treatment of gastroparesis is still under investigation. These procedures should only be considered after careful discussion and review of all alternatives in selected patients with special circumstances and needs.

Humanitarian Use Device Exemption
The Enterra Therapy system for gastric electrical stimulation to treat chronic nausea and vomiting in gastroparesis is approved by the U.S. Food and Drug Administration (FDA) as a Humanitarian Use Device. What does this mean? The FDA has a specialized process, which was established by Congress for developing treatments for rare disease populations, the Humanitarian Use Device (HUD) process. Devices reviewed and approved through this process receive a Humanitarian Device Exemption (HDE).

Despite the fact that these devices are reviewed and approved by FDA, since they were not approved through the standard process many insurance companies will deem them “investigational” and refuse to cover the procedures. In these cases, the cost of the treatment alone can be enough to significantly restrict patient access. While Enterra is not for everyone, some individuals benefit greatly and can be restored to a productive lifestyle. The fact that individuals seeking Enterra or other beneficial rare disease treatments may be denied access to the treatment by a third-party payer is an issue that needs to be addressed.

Be sure to ask questions so you understand any treatment and options, know the risks as well as benefits, and know what to do if side effects occur or symptoms return.

Keep hydrated and as nutritionally fit as possible. Persistence pays off, as most people with gastroparesis ultimately will do well.

Reference:

1. NIH, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Gastroparesis Clinical Research Consortium.  (Accessed January 16, 2018)

Copyright © 2019 International Foundation for Functional Gastrointestinal Disorders (IFFGD). All rights reserved.

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