Gastroparesis (GP), or delayed gastric emptying, is a condition in which the stomach’s ability to empty its contents is impaired, unrelated to obstruction. There are three main forms of the condition: diabetic, post-surgical and idiopathic, where the common cause is unknown. Gastroparesis is one of the common gastrointestinal complications of diabetes. Patients with scleroderma, those on anticholinergic medications commonly used for treatment of conditions such as asthma and Parkinson’s disease, and those who have had surgery for treatment of a duodenal ulcer may also suffer from gastroparesis.
It is undetermined whether gastroparesis is a progressive condition. “Overall, when patients get to the refractory stage, when they need referral to tertiary care, about one third of them keep on continuing to decline,” says Henry Parkman, MD, gastroenterologist, associate professor of medicine, Temple University Hospital, Philadelphia. “You can maintain about one third of them by trying to change medicines. One third of those, somehow, will spontaneously remit.”
Oddly, says Parkman, gastroparesis is more common in women, usually in their 20s to 30s. “We think it might be related to the inhibital effects of female hormones,” he says.
Common symptoms of gastroparesis include nausea, vomiting and abdominal pain. Severe gastroparesis might result in recurrent hospitalizations, malnutrition and significant mortality. Patients failing medical therapy are often considered for a variety of surgical interventions, the efficacy of which is not well studied.1
In evaluating patients, often an endoscopy will be performed to make sure they don’t have an ulcer or some sort of malignancy or obstruction causing the symptoms, says Parkman.
Treatments for gastroparesis include eating small meals throughout the day and avoiding fatty foods and other foods that are difficult to digest. “Initially, if the symptoms are very mild, you might change the diet to low fat, low fiber, and see how that works,” says Parkman. “Sometimes that helps the very mild cases.”
If the condition is a complication of diabetes, intensifying insulin therapy to better control blood glucose may be recommended. A number of drug therapies are also used to treat the symptoms of gastroparesis. “We try two kinds of medications,” says Parkman. “Prokinetic, which speeds things along, and antiemetic, which suppress symptoms.” Metoclopramide, which increases the movements or contractions of the stomach and intestines, is among the most effective. While the antibiotic erythromycin improves stomach emptying, its side effects of nausea, vomiting and abdominal cramps limit its usefulness. One additional drug, Domperidone, is not yet approved for use in the U.S., but is under review by the U.S. Food and Drug Administration. Domperidone improves stomach emptying by stimulating stomach motor activity, relieves nausea, and has few side effects.
Jejunal feeding tubes
A PEJ tube can be placed endoscopically by a gastroenterologist and is often an outpatient procedure. The procedure is performed by placing a tube down the patient’s esophagus, through the stomach, and into the first portion of the jejunum. When the doctor finds a good location, a light is shined through the skin and the incision is made. The tube is inserted and a hard bolus is placed on the inside of the intestines to keep the tube from coming out.
A j-tube can be placed either laparoscopically or through an open procedure. Typically, it is placed laparoscopically unless the patient is not a candidate due to adhesions from previous surgeries or other complications. Usually after a surgical placement the patient will remain in the hospital at least for a few days as the nutrition is started very slowly until the patient is tolerating the feedings well enough to go home under the care of a home health care agency. Complications of the j-tube include pain, bowel obstruction, not tolerating feedings, and skin and internal infections. However, the complications are usually less serious than those associated with IV nutrition and therefore the j-tube is a good alternative for someone in need of longterm nutritional support.2
A g-tube (or PEG) is a feeding tube that is inserted into the patient’s stomach. Although typically not an ideal solution for feeding a person with gastroparesis due to the delayed gastric emptying, it does provide some patients with a way to better control the nausea and vomiting by providing a “burp” valve which allows the patient to drain out the stomach as needed. Typically, a g-tube is placed at the same time and in the same manner as a j-tube (or PEJ).3
“The PEG tube is used for feeding in [for example] stroke patients with oralphyrengeal dysphasia,” says Parkman. “But we don’t want to feed into the stomach because that’s the problem — they can’t empty; the stomach muscle doesn’t move. Some people have been endoscopically putting in G tubes with J extensions. We don’t do that here — we don’t believe in that, but some people do. We think that the J tube ends up migrating back into the stomach. Some centers do it, and they do it well, but our experience hasn’t been so good. A G tube with a J extension can be used for simultaneous G tube decompression and J tube feeding. You bypass the stomach with the feeding.”
A pyloroplasty is performed to help the stomach empty foods more easily. The surgeon cuts into the pyloric muscle and to the mucosa, which basically makes a larger opening at the bottom of the stomach for food to digest more easily by gravity. This surgery can often cause complications such as dumping syndrome in which the stomach empties too quickly and therefore causes other complications in a patient with GP.
A gastrectomy is usually a last resort for patients with GP. It involves the removal of all of the stomach (total gastrectomy) or part of the stomach (partial gastrectomy). After the stomach has been removed, the intestines are brought up and attached to the esophagus. In the case of a partial gastrectomy, the intestines are attached to the remainder of the stomach.
In a total gastrectomy, the surgeon may leave a small pouch of stomach to attach to the intestines, if possible. It can be effective in some people and improve quality of life. The results after a gastrectomy may not be felt for months, but side effects are completely different from GP symptoms. In a lot of cases, the patient is able to eat fairly normally after a year or two. Most patients cannot eat perfectly normal, but feel the improvement in eating was worth the operation.
Gastric Electrical Stimulators
Some hospitals are now implanting Enterra™ Therapy, or Gastric Electrical Stimulators (GES), which are manufactured by Medtronic. Since the stomach is a muscle like the heart, doctors have been working on creating a device that will stimulate the nerves in stomach for patients with GP. It may improve the symptoms of nausea and vomiting by stimulating certain nerves within the stomach. It may also improve gastric dysrhythmias, which can improve nausea as well. It can be placed laproscopically or through an open procedure depending on the individual patient. It is not a cure for GP, but instead a treatment that helps some patients eat better with decreased and/or no nausea and vomiting.
A number of studies have been performed to investigate the effects of GES on gastric motility, gastric emptying, and gastrointestinal symptoms in both dogs and humans. Based on the frequency of the electrical stimulus used for chronic treatment of gastroparesis, gastric electrical stimulation can be classified into lowfrequency stimulation (LFS) and high-frequency stimulation (HFS). Although some of the results are still controversial, the majority of these studies seem to indicate that LFS is able to normalize gastric dysrhythmias and entrain gastric slow waves and accelerate gastric emptying. On the other hand, HFS has no effect on gastric emptying but is able to significantly reduce symptoms of nausea and vomiting in gastroparetic patients. 4
A multicenter, Worldwide Anti-Vomiting Electrical Stimulation Study (WAVESS) trial successfully studied 33 patients who had gastric stimulators. This was a double blind crossover study. During the next 12 months, the WAVESS study group reported over 50 percent improvement in relief from vomiting and increase in resulting quality of life. Also this study group had a 30 percent reduction in hospital use in the first year after implantation of the gastric stimulator. Analysis of nutritional outcome showed significant increase in BMI (Body Mass Index). In addition, 75 percent of patients who were requiring jejunal feeding tubes had the tubes removed within 6 months and were eating. Based on the WAVESS data, the FDA approved Enterra therapy in March 2000 under a Humanitarian Device Exemption.
Gastric electrical stimulation implantation resulted in improvement of nutritional parameters throughout the first 12 months, as nausea and vomiting decreased and oral intake increased. This improvement in nutritional measures is maintained long-term and is associated with improvements in quality of life. Gastric electrical stimulation should be considered as a therapeutic option for any patients with refractory GP and nutritional compromise.5
Botulinum toxininjection into the pylorus is reported to improve gastric emptying in gastroparesis. “We did a study of 10 patients with idiopathic GP,” says Parkman. “We injected Botox, or botulinum toxin. It actually works by decreasing the release of the acetylcholine, an excitatory transmitter. By decreasing the release of that excitatory transmitter, you end up relaxing the pylorus, the final sphincter out of the stomach. So you relax the pylorus, and hopefully improve the stomach emptying. Our study showed that we were able to improve symptoms, and we were able to improve gastric emptying. Although it’s easy and it’s done quite a lot, it’s only temporizing. Botox only lasts for three months. It also has never been shown in a double blind, placebo controlled trial. All of the studies were open label.”
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|SYMPTOMS of GP|
Signs of gastroparesis include:
These symptoms may be mild or severe, depending on the individual.