What is Gastric Outlet Obstruction?
Gastric outlet obstruction, or GOO, is a condition that can cause several symptoms, such as stomach pain, vomiting after meals, feeling full quickly, and losing weight. These symptoms arise because something is causing a block or preventing the stomach from emptying properly. The obstruction can either be benign (not harmful in the long term) or malignant (potentially harmful) and can occur at the lower part of the stomach, the outlet of the stomach (pyloric channel), or the first part of the small intestine (duodenum). Additionally, this obstruction can either come from within the stomach or from outside of it.
What Causes Gastric Outlet Obstruction?
Gastric Outlet Obstruction (GOO), a condition where your stomach is blocked and prevents food and drink from passing through, can be caused by two main things:
1. Physical blockage (benign or cancerous)
2. Problems with stomach movements
The first category can be a ‘good’ or benign blockage. This could occur due to a variety of factors such as:
* Stomach ulcers
* The use of nonsteroidal anti-inflammatory drugs (NSAIDs, like ibuprofen)
* Inflammation due to a bacteria called Helicobacter pylori
* Abnormal growths known as polyps
* Swallowing harmful substances
* An infection of the stomach known as gastric tuberculosis
* Narrowed areas formed after surgery (anastomotic strictures)
* Inflammatory bowel disease, known as Crohn’s disease
* Hard masses of indigestible material in the stomach (gastric bezoars)
* Twisting of the stomach (gastric volvulus)
* An inflammatory condition of the gastrointestinal tract (eosinophilic gastroenteritis)
* Gall stones getting stuck in pylorus or proximal duodenum, known as Bouveret syndrome
* A rare congenital condition where the pancreas encircles the duodenum (annular pancreas)
* Inflammation of the pancreas, referred to as pancreatitis
These causes typically affect the lower part of the stomach and the duodenum (the first part of the small intestine), but the lower part of the small intestine can also be affected.
The cause could also be a bad or malignant blockage from cancer. This usually happens in the area of the stomach and first part of the intestine and accounts for up to 35% of GOO causes. Cancers might include pancreatic, gastric lymphoma, or advanced gallbladder carcinoma among others. They make up 15%-25% of cases.
The second category involves problems with the stomach’s natural movements, or ‘motility’. The main cause of these is a condition called gastroparesis, where the stomach takes too long to clear out food. Sometimes the cause isn’t clear but diabetes is a common underlying factor. Other causes can include viral illnesses, certain medications, damage to a nerve during surgery, or complications from some cancers.
Understanding the cause of Gastric Outlet Obstruction helps doctors to identify the right treatment option for each patient.
Risk Factors and Frequency for Gastric Outlet Obstruction
GOO, or gastric outlet obstruction, is a medical condition whose exact numbers are not fully known. In the past, this condition was primarily caused by ulcers, but now those make up only 5% of all cases. This decrease is due to better treatments for infections and the use of a certain type of medication called proton pump inhibitors (PPIs). Nowadays, between 50% and 80% of GOO cases are caused by underlying cancers. About 15% to 20% of those cases are caused by a specific type of cancer in the area around the pancreas. Data shows that more males than females suffer from this illness, with the ratio being approximately 3 to 4 males for every female.
An issue known as hypertrophic pyloric stenosis (HPS), is a common cause of GOO in newborn babies. This problem arises when the muscles in a part of the stomach get too large and narrow down the stomach’s opening, causing blockage. It affects between 1.5 to 3 out of every 1000 newborns, and significantly more commonly in baby boys than girls. However, the condition very rarely occurs in older children and teenagers. It’s also a leading reason for surgery during the first six months of a baby’s life.
- GOO used to be mainly caused by ulcers but this has decreased to 5% due to improved treatments and use of PPIs.
- 50% to 80% of GOO cases are now due to underlying cancers.
- 15% to 20% of these cases are caused by cancer around the pancreas.
- Males are more affected by GOO than females, with ratios being around 3 to 4 males for each female.
- A condition called hypertrophic pyloric stenosis is a common cause of GOO in newborns, particularly males.
- This condition is the main reason for surgery in babies during the first half year of their lives.
Signs and Symptoms of Gastric Outlet Obstruction
Gastric Outlet Obstruction (GOO) is a condition that can stem from a variety of causes. The onset and range of symptoms depend on what’s causing the obstruction. Commonly people experience nausea and vomiting. Sudden symptoms might make doctors suspect conditions like gallstones, pancreatitis, peptic ulcers, volvulus (a type of bowel obstruction), or tube migration in those using PEG-tubes. Non-malignant causes usually bring about feelings of early fullness (53%) and bloating (50%), whereas, more serious causes may result in pain, vomiting, weight loss, and malnutrition.
During a physical exam, doctors may find signs of decreased blood volume (hypovolemia), weight loss, and abdominal bloating. Around 25% of patients may exhibit a succussion splash, which is a distinctive sound heard upon shaking the stomach, suggesting trapped stomach material. If this sound is heard more than 4 hours after a meal, it may indicate GOO with a 50% chance.
It is also important to know a patient’s medication history, especially the use of drugs like NSAIDs, aspirin, opioids, and anticholinergic medications. Smokers should be instructed and guided to stop smoking.
Testing for Gastric Outlet Obstruction
If you’ve been continually vomiting, there’s a chance your body may be low on potassium (hypokalemia) and also be experiencing what’s called hypochloremic metabolic alkalosis. It’s a fancy term, but it just means your body’s fluids have too much alkaline, or base. This occurs due to the loss of acidic stomach juices from vomiting.
Sometimes, your stomach can look bloated due to this condition, and it can indirectly lead to higher levels of a hormone called gastrin in your blood.
Plain X-rays may show unusually big bubbles of gas in your stomach that don’t extend to the middle of your body. If the obstruction is large enough, the small intestines may not even be visible on the X-ray. Additional tests using either barium or a water-soluble contrast solution can help doctors better understand what’s causing the blockage. If this contrast material fails to reach the small intestines, it suggests a total blockage.
A CT scan can provide even more detailed information like the thickness of the muscle that controls food from your stomach to your small intestine (pylorus) or the stomach wall. It can also show if lymph nodes are swollen or if there are growths on the pancreas.
Endoscopy is a procedure often needed to better understand and confirm the cause of the obstruction. This involves a thin, flexible tube, equipped with a light and tiny camera at one end, being inserted through your mouth and down your esophagus to visualize what’s going on in your stomach. To reduce the risk of inhaling, or aspirating, stomach contents during endoscopy, a tube is inserted through your nose into your stomach and suction is applied to remove these contents.
Once your stomach is decompressed, a saline load test can be undertaken to further evaluate your situation. Here, a large amount of saline solution (750 ml) is delivered into your stomach through a tube. If more than 400 mL of your stomach contents are retrieved after 30 minutes, it’s considered a positive test for obstruction.
And lastly, tissue samples collected during endoscopy can help confirm or rule out a cancerous cause for the obstruction.
Treatment Options for Gastric Outlet Obstruction
If your stomach is blocked (a condition known as gastric outlet obstruction or GOO), your treatment options will vary depending on what is causing the obstruction and how severe it is.
In cases where a benign or non-cancerous condition, like a peptic ulcer disease, causes the blockage, doctors usually try to manage it with medicines first. These may include acid reducers, avoiding non-steroidal anti-inflammatory drugs (NSAIDs), and treatments for the bacteria H. pylori. If these don’t work, your doctor may look at options like endoscopy or surgery.
During an endoscopy, a doctor uses a special device to get a close look at the blocked area in your stomach or small intestine. If there’s a stricture or narrowing, a process called endoscopic balloon dilation (EBD) can be used to expand the blockage. The doctor will insert a balloon dilator through a scope or place a balloon over a guidewire with the help of fluoroscopy. It might require several sessions to achieve the desired results.
The response to EBD generally varies based on the cause of the stricture. For instance, strictures caused by caustic or harmful substances are harder to treat because they cause more damage to the tissue, leading to scarring. However, most patients see almost immediate symptom improvement with EBD.
If EBD fails to solve the issue, other techniques, such as placing a self-expandable metal stent (SEMS) in the blocked area, might be considered. SEMS have proven to be an efficient solution when EBD fails, but there isn’t extensive evidence about their effectiveness in benign GOO.
Surgical intervention could also be an option if non-invasive treatments don’t work or if the obstruction is causing serious complications. In particular, GOO caused by extrinsic compression, like chronic pancreatitis, is less likely to respond to balloon dilation and might need early surgical intervention.
If your stomach blockage is caused by a cancerous or malignant condition, the treatment options are different. Resection (surgical removal), decompressive gastrostomy (removing the blockage), bypass surgery, endoscopic stenting, and EUS (endoscopic ultrasound)-guided gastrojejunostomy (creating a bypass) are some of the available treatments. Surgery is often the best choice if it can potentially cure the patient.
Before surgical bypass, the severity of the disease is often examined using either laparoscopy or exploratory surgery. If the blockage is not treatable with surgery, percutaneous decompressive gastrostomy, a procedure draining the stomach, can be used for relief.
For patients with a short life expectancy, SEMS placement could be a palliative measure to relieve symptoms and improve quality of life.
Other treatment options include EUS-guided gastrojejunostomy using lumen-apposing metal stents. This procedure involves creating a bypass by inserting a stent from the stomach to the small bowel beyond the obstruction. It can be useful for treating both malignant and benign GOO.
What else can Gastric Outlet Obstruction be?
If a young person has symptoms that suggest a blockage in their stomach (known as gastric outlet obstruction or GOO), there could be several possible causes. It could be due to a birth defect causing a blockage like diaphragms, webs, blocks inside the lining or abnormal pancreas growth. On the other hand, the issues could also be due to:
- Cancerous growth (Neoplasm)
- Damage from chemicals (Chemical Injury)
- A rare condition that affects the body’s ability to fight infection (Chronic granulomatous disease)
- A condition where stomach bulges into the chest through an opening (Hiatal hernia)
- A rare tumor in the stomach lining (Brunner gland adenoma)
- Birth defects causing webs in the small intestine (Congenital duodenal webs)
- Fluid-filled sacs in the pancreas (Pancreatic pseudocysts)
- Blockage due to gallstones (Gallstone obstruction)
- An intense infection caused by a specific parasite (Strongyloides hyperinfection)
These are all conditions that the doctor would need to consider when trying to find out the root cause of the symptoms.
What to expect with Gastric Outlet Obstruction
If you have a medical condition known as Gastric Outlet Obstruction (GOO), which results from long-term Peptic Ulcer Disease (PUD), it is usually suggested that you undergo surgery sooner rather than later. Without this surgery, there’s a high chance for the obstruction to occur again, severe bleeding, or even the formation of a hole in the stomach or bowel. Getting early treatment for PUD generally leads to a good outcome.
However, if the GOO is a result of cancer, the prospects are typically not as positive compared to other causes of this condition.
Possible Complications When Diagnosed with Gastric Outlet Obstruction
People who receive an endoscopic treatment, which could be either a balloon dilation or stenting, can experience a risk of perforation or a tearing of the body tissue. For benign peptic stenosis, or narrowing of the digestive tract due to non-cancerous ulcers, the risk of this tear happening during the balloon dilation process is usually between 3% and 6%. However, this goes up if the diameter of the balloon is more than 15 mm.
During the procedure of endoscopic balloon dilation (EBD), minor bleeding and pain can occur, but these usually resolve by themselves. Severe malnutrition is a major issue for patients with a gastric outlet obstruction (GOO). Therefore, prior to surgery, these patients should be given parenteral nutrition, which supplies nutrients directly to the bloodstream, for at least one week to properly prepare them for the procedure.
Risks of Endoscopic Treatments:
- Tearing of body tissue
- Bleeding
- Pain
Potential Complications:
- Severe malnutrition for gastric outlet obstruction patients
Preparation for Surgery:
- Receiving parenteral nutrition at least one week before the procedure
Preventing Gastric Outlet Obstruction
If you have a condition known as gastric outlet obstruction, or GOO for short, you might find yourself vomiting quite often. This is typically the first sign of the problem. If your doctor suspects you have GOO, they’ll carry out some prompt tests to identify what’s causing the blockage. Depending on what’s causing it, the treatment can vary a lot.
If the GOO is benign, or not harmful and caused by peptic ulcer disease (PUD), changes to your lifestyle are the main way to treat it. This involves things like reducing the amount of acid in your stomach, steering clear from nonsteroidal anti-inflammatory drugs (NSAID), quitting smoking, and getting tested and treated for a bacteria called H. pylori. All these actions can help manage the condition effectively.
