Gastroparesis refers to severely delayed gastric emptying in the absence of any obstruction at the gastric outlet or farther downstream in the small bowel.
Causes and epidemiology:
Gastroparesis is more common in women, and the average age of onset is in the fourth decade of life.
The most common causes of gastroparesis are type II diabetes and post-surgical conditions such as vagotomy. In diabetes, autonomic neuropathy and hyperglycemia are both thought to slow gastric emptying, with solid food affected more than liquids. Similarly, in a post-vagotomy state, gastric emptying of solids is delayed while emptying of liquids is accelerated.
Symptoms most commonly associated with gastroparesis are chronic nausea, vomiting, early satiety, and post-prandial fullness. Gastroparesis may be associated with either weight loss or weight gain, abdominal pain, reflux, and anorexia.
A gastric emptying study remains the gold standard in the diagnosis of gastroparesis. Radionucleotide-labeled solids and liquids are administered, and transit times are measured with a gamma camera. The 4-hour residual following a low-fat egg meal is the most sensitive and specific for detecting gastroparesis.
Dietary measures are directed at low-fat, low-fiber, small, and frequent meals coupled with good glycemic control. A higher percentage of liquid nutrition is also encouraged since gastroparesis tends to affect transit of solids more than liquids. Prokinetic drugs such as Reglan and Erythromycin are sometimes used, but their efficacy in treating gastroparesis is questionable.
In cases of severe weight loss, a feeding jejunostomy tube may be placed for nutritional support.
The most common procedure performed for symptomatic relief is implantation of an electrical gastric pacemaker, which delivers electrical pulses to the smooth muscle along the greater curvature. While gastric pacemakers have not been shown to increase gastric emptying, they have been reported to improve gastrointestinal symptoms, nutritional status, and overall quality of life.
Partial or subtotal gastrectomy has been proposed for refractory cases, with anecdotal reports suggesting that symptoms may be alleviated in the majority of patients.