Description
Gastroparesis, commonly known as delayed gastric emptying, is a condition characterised by a reduction or absence of normal spontaneous peristalsis in the stomach, resulting in the delayed emptying of food contents. The failure in gastric motility is usually due to vagal nerve dysfunction. It’s a chronic, often debilitating condition that can lead to a variety of complications.
Pathogenesis
The aetiology of gastroparesis is multifactorial, encompassing various pathological mechanisms:
- Idiopathic gastroparesis (50%)
- Diabetic gastroparesis: Resulting from uncontrolled diabetes mellitus, which leads to vagus nerve damage.
- Drug-induced gastroparesis: Third most common cause. Due to certain medications like narcotics and some types of antidepressants.
- Post-surgical gastroparesis: Occurs after surgeries that damage the vagus nerve, or following fundoplication, pancreaticoduodenectomy.
Epidemiology, Risk Factors & Associations
The condition is more common in females than males (female-to-male ratio is about 4:1). Prevalence is estimated at about 24 in 100,000 persons for men and 38 in 100,000 persons for women. Diabetes, especially type 1, is a major risk factor, with gastroparesis affecting about 5% of individuals with diabetes. Other risk factors include:
- Prior gastric or abdominal surgery
- Medications such as narcotics and some antidepressants
- Neurological conditions like Parkinson’s disease
- Connective tissue disorders like scleroderma
Clinical Features
Symptoms can range from mild to severe and typically include:
- Nausea and vomiting
- Early satiety
- Postprandial fullness
- Abdominal pain
- Bloating
- Weight loss
Complications
- Severe dehydration due to persistent vomiting
- Malnutrition from poor absorption of nutrients
- Development of bezoars (hard, solid collections of food or other material that can block the digestive tract)
- Unpredictable blood sugar changes in individuals with diabetes
Pathological Features
Histopathology
Histological findings can vary but may show:
- Fibrosis and hyaline degeneration in the muscularis propria
- Reduction in the number of interstitial cells of Cajal (the pacemaker cells of the gastrointestinal tract)
- Inflammation in the myenteric plexus
Serology
- Mildly elevated blood glucose levels in diabetic gastroparesis
- Altered gut hormone levels in response to feeding
Radiological Features
General Features
- Imaging typically shows a distended stomach, delayed gastric emptying without evidence of mechanical obstruction. Gastric emptying study is the most common diagnostic test, which measures the speed with which food leaves the stomach.
- Evidence of surgery such as surgical staples or changes in the anatomy of the stomach may be observed.
NM
- Gastric Emptying Scintigraphy: Gold standard for diagnosing gastroparesis (highly sensitive). Involve ingestion of Tc99m mixed into a solid meal (eggs or oatmeal). Gamma camera captures images over several hours to monitor the process of gastric emptying. If more than 10% of the meal is still present in the stomach after 4 hours, this is typically interpreted as delayed gastric emptying, suggestive of gastroparesis.
Grading and Staging
There isn’t a universally accepted system for grading or staging gastroparesis, but severity of symptoms and the rate of gastric emptying can guide treatment.
Differential Diagnosis
- Functional dyspepsia: Overlapping symptoms but typically no evidence of delayed gastric emptying.
- Peptic ulcer disease: Symptoms may mimic gastroparesis, but usually associated with epigastric pain and gastric mucosal injury visible on endoscopy.
- Gastric Outlet Obstruction: Often due to mechanical causes such as peptic ulcer disease, gastric polyps, or malignancies like gastric carcinoma. On upper GI series or CT scan, signs of obstruction such as dilated stomach and proximal duodenum, possibly with a transition point, can be seen. Evidence of the underlying cause, such as ulcer craters or mass lesions, may also be visible.
- Intestinal Scleroderma: A systemic autoimmune disease that can involve the stomach and result in delayed gastric emptying due to fibrosis and loss of motility. On CT, evidence of bowel wall thickening, luminal narrowing, and a ‘hide-bound’ appearance due to fibrosis can be seen. Barium studies may show similar findings and reduced motility.
- Cystic Fibrosis: A genetic disorder affecting multiple organ systems, including the gastrointestinal tract. Delayed gastric emptying is a common complication. On imaging, evidence of other manifestations of cystic fibrosis, such as pancreatic atrophy or bronchiectasis, may be seen.
- Gastric Bezoar: Hard, indigestible mass trapped in the stomach can cause symptoms similar to gastroparesis, particularly if large. On CT or abdominal X-ray, a well-defined intraluminal mass can be seen, often with a mottled or ‘mixed’ appearance due to varying densities within the bezoar.
Management
- Gastroparesis is managed with a multidisciplinary approach involving gastroenterologists, dietitians, and sometimes, surgeons.
- The goals are to manage symptoms and maintain adequate nutrition.
- Dietary modifications are typically the first step.
- Medications can be used to stimulate gastric emptying or manage nausea.
- In severe cases, or when other treatments fail, interventions like a gastric pacemaker or feeding tube may be necessary.