An Approach to Gastric Outlet Obstruction
Doctor, I am vomiting old food!
Introduction
Differential Diagnosis
Evaluation Priorities
Context: Emergency Unit
Introduction
The pathology almost always is in the antrum of the stomach or first part of the duodenum. Oesophageal obstruction will usually cause dysphagia, not vomiting, and more distal obstruction is characterized as SBO.
Patients typically present vomiting partly digested old food; since the site of obstruction is above the Ampulla of Vater, there is no bile staining.
Other associated symptoms are repeated burping, halitosis, and "heartburn" type symptoms. Patients will vomit intermittently, once or twice a week, and will have lost weight by the time they seek medical attention. Abdominal pain is hardly ever a feature of GOO.
On examination, pay specific attention to signs of dehydration, weight loss, anaemia, jaundice and supra-clavicular adenopathy. Abdominal examination may reveal an epigastric mass or succession splash.
Differential Diagnosis
Common causes (>95%) |
Gastric carcinoma Peptic ulcer (gastric or duodenal) Extrinsic compression by pancreatic pathology
|
| Unusual |
In the lumen Gallstone, food bolus or foreign body obstruction In the wall Crohn's Disease TB Other GI neoplasm
Gastric volvulus Duodenal bands SMA syndrome DysmotilityGastroparesis
|
Evaluation Priorities
How bad is this?
- Rehydrate the patient, and correct the expected electrolyte derangements.
- Nasogastric tube drainage and lavage the stomach flavoured isotonic saline solution for 2-3 days - this empties the stomach of old food that would obscure endoscopy.
- Admit to the ward.
- GOO does not require emergency intervention
What is the cause?
| Gastric carcinoma | Epigastric mass, anaemia and adenopathy |
| Peptic ulcer | History of NSAID’s |
| Carcinoma pancreas | Mass, anaemia and adenopathy, jaundice |
| Chronic pancreatitis | Alcohol history, episodes of pain, steatorrhoea |
| Corrosive stricture | Psychiatric history, recent suicide attempt with ingestion of corrosives |
What other investigations must I consider?
- The key investigation is an upper GI endoscopy.
- This will confirm the diagnosis and differentiate between gastric carcinoma and a peptic ulcer.
- All gastric ulcers MUST be biopsied - an eyeball test is not good enough!
- It is best to delay endoscopy by 2-3 days in order to prepare the stomach properly.
- An US or CT scan may be helpful in cases of pancreatic pathology, or to stage further a newly diagnosed gastric carcinoma.
Real Problem Scenarios!
The stomach is full of food on endoscopy!
- It confirms the patient has GOO!
- Delay x 48 hours and lavage the stomach
- Repeat scope
The endoscopy can't see a mucosal lesion, there is nothing to biopsy!
- Book a CT scan to see if there is pancreatic compression or a pseudocyst
The gastric ulcer looks like cancer, but the biopsy is negative!
- Discuss with your consultant
- How many biopsies were taken (a minimum of 4 must be taken in each case!)
- Consider a repeat endoscopy and re-biopsy
When must we operate?
- Not every case needs surgery, and management must be individualized depending on the aetiology
- Some PU can be treated with balloon dilation and medications
- GCA and HOP Ca may be palliated with a stent
- Pancreatic pseudocyst may be drained internally via endoscopy