What is the initial workup and management for a patient with gastric outlet obstruction?

Initial Workup and Management for Gastric Outlet Obstruction

The initial workup for gastric outlet obstruction should include a complete history and physical examination, laboratory tests, abdominal imaging, and endoscopy, followed by management based on the underlying cause, with a multidisciplinary approach involving oncologists, surgeons, and endoscopists to determine the optimal intervention strategy. 1

Initial Assessment

• Obtain a detailed history focusing on symptoms such as nausea, vomiting (especially postprandial), epigastric pain, early satiety, and weight loss 1
• Physical examination should assess for abdominal distension, visible peristalsis, and a succussion splash 1
• Digital rectal examination should be performed to detect blood or rectal mass if colorectal malignancy is suspected 1
• Evaluate vital signs to identify potential complications such as hypovolemic shock from dehydration or septic shock if perforation has occurred 1

Laboratory Evaluation

• Complete blood count to assess for anemia and leukocytosis 1
• Comprehensive metabolic panel to evaluate renal function, electrolytes, and liver function 1
• Serum bicarbonate, arterial blood pH, and lactic acid levels to identify potential intestinal ischemia 1
• Coagulation profile in preparation for potential surgical intervention 1

Imaging Studies

• Abdominal plain X-ray as the first-line radiologic study (50-60% diagnostic in small bowel obstruction) 1
• Water-soluble contrast studies have 96% sensitivity and 98% specificity in diagnosing large bowel obstruction 1
• CT scan with oral and IV contrast to determine the location, cause, and extent of obstruction 1, 2

Endoscopic Evaluation

• Upper endoscopy is essential to:
  • Visualize the obstruction
  • Obtain biopsies to determine if the cause is malignant
  • Assess the feasibility of endoscopic intervention 1, 2

Initial Management

• Supportive care:
  • Intravenous fluid resuscitation with isotonic crystalloids 1
  • Nasogastric tube placement for decompression and prevention of aspiration pneumonia 1
  • Foley catheter insertion to monitor urine output 1
  • Anti-emetics for symptom control 1
  • Bowel rest 1

Management Based on Etiology

For Malignant Gastric Outlet Obstruction

1. For patients with good functional status, life expectancy >2 months, and who are surgically fit:

   • Surgical gastrojejunostomy is recommended 1
   • Laparoscopic approach is preferred over open approach due to lower blood loss and shorter hospital stay 1

2. For patients who are not candidates for gastrojejunostomy:

   • Endoscopic placement of self-expanding metal stents (SEMS) is recommended 1
   • SEMS provides faster symptomatic relief, shorter hospital stays, and more rapid resumption of oral intake compared to surgery 1, 2, 3

3. For patients with multiple luminal obstructions or severely impaired gastric motility:

   • Enteral stents should not be used due to limited benefit 1
   • Consider placement of a venting gastrostomy 1

4. For experienced endoscopists:

   • Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is an acceptable alternative to surgical gastrojejunostomy and enteral stent placement 1, 4
   • EUS-GE may provide the minimal invasiveness of an endoscopic procedure with the long-lasting effect of surgical gastrojejunostomy 3, 4

For Benign Gastric Outlet Obstruction

• Treat underlying cause (e.g., proton pump inhibitors and H. pylori eradication for peptic ulcer disease) 5
• Endoscopic balloon dilation for benign strictures 5, 6
• SEMS placement for refractory benign disease 6
• Surgery remains the last resort for benign disease 6

Special Considerations

• Ascites, if present, should be drained before venting gastrostomy tube placement to reduce infectious complications 1
• Severe uncontrolled pain after gastric stent placement should be treated with immediate endoscopic removal of the stent 1, 2
• Nutritional support via feeding gastrostomy tubes for EGJ/gastric cardia obstruction or jejunal feeding tubes for distal gastric obstruction may be necessary 1

Monitoring and Follow-up

• Regular assessment of oral intake tolerance 7
• Monitoring for stent migration or tumor ingrowth requiring reintervention 3, 7
• Surveillance for development of biliary obstruction, which occurs in up to 44% of patients with malignant gastric outlet obstruction 7

Pitfalls and Caveats

• Stent placement may be more appropriate for patients with shorter life expectancy, while gastrojejunostomy is preferable for those with longer prognosis 1, 3
• Stent migration is a common complication requiring endoscopic repositioning or replacement 2
• Surgical gastrojejunostomy has more durable relief of symptoms but at the cost of higher procedure-related risks and longer hospital stay 3
• EUS-GE is promising but requires experienced endoscopists and may not be available at all centers 4