Gastric outlet obstruction

Gastric Outlet Obstruction (GOO) is a medical condition where there is a blockage at the pylorus, which is the opening from the stomach into the duodenum. This obstruction can impede the passage of gastric contents into the small intestine, leading to symptoms such as vomiting, abdominal pain, and bloating. Gastric outlet obstruction can be caused by a variety of factors, including peptic ulcer disease, gastric cancer, and pancreatic cancer, as well as benign conditions like pyloric stenosis.

Causes

Gastric outlet obstruction can be classified based on its causes into two main categories: benign and malignant.

Benign Causes

• Peptic Ulcer Disease: The most common benign cause, where ulcers form in the stomach or duodenal lining and heal with scarring, leading to narrowing of the pylorus.
• Pyloric Stenosis: This is more common in infants and involves thickening of the pyloric muscle, leading to obstruction.
• Gastritis and duodenitis: Inflammation of the stomach and duodenum can lead to swelling and blockage.
• Bezoars: Accumulation of indigestible material can physically block the gastric outlet.

Malignant Causes

• Gastric Cancer: Tumors in the stomach can grow to obstruct the pyloric canal.
• Pancreatic Cancer: Tumors in the pancreas can press on the stomach or duodenum, causing obstruction.
• Other cancers that metastasize to the stomach or surrounding areas can also lead to GOO.

Symptoms

Common symptoms of gastric outlet obstruction include:

• Persistent vomiting, which may include undigested food
• Abdominal bloating and pain
• Early satiety
• Weight loss and dehydration due to difficulty in food and fluid intake

Diagnosis

Diagnosis of gastric outlet obstruction involves a combination of clinical history, physical examination, and diagnostic tests, including:

• Upper gastrointestinal series: An X-ray test that shows the shape of the stomach and the presence of any blockages.
• Endoscopy: A procedure where a flexible tube with a camera is inserted through the mouth to visualize the stomach and duodenum.
• CT scan: Can provide detailed images of the stomach, duodenum, and surrounding structures to identify the cause of obstruction.

Treatment

Treatment of gastric outlet obstruction depends on the underlying cause and the severity of symptoms. Options include:

• Surgery: Surgical intervention may be necessary to remove the obstruction, especially in cases of malignancy.
• Endoscopic balloon dilation: For benign causes, stretching the narrowed area with a balloon can relieve obstruction.
• Medications: Proton pump inhibitors or H2 receptor antagonists can reduce acid production, aiding in the healing of peptic ulcers.
• Stenting: In some cases, especially with malignant obstruction, a stent may be placed endoscopically to keep the pylorus open.

Prognosis

The prognosis for gastric outlet obstruction varies widely depending on the underlying cause. Benign conditions often have a good outcome with appropriate treatment, while malignant causes may have a poorer prognosis depending on the stage and nature of the cancer.