How should gastric outlet obstruction be initially stabilized, investigated with imaging and endoscopy, and managed medically, endoscopically, or surgically for benign versus malignant etiologies?

Management of Gastric Outlet Obstruction

Initial Stabilization

Immediately place a nasogastric tube for gastric decompression to prevent aspiration pneumonia and relieve symptoms, while simultaneously initiating IV isotonic crystalloid resuscitation to correct dehydration and electrolyte abnormalities from vomiting. 1, 2

• Administer anti-emetics such as metoclopramide or prochlorperazine for symptom control 1, 2
• Insert a Foley catheter to monitor urine output and assess adequacy of resuscitation 2
• Maintain bowel rest until the obstruction is definitively addressed 2

Diagnostic Workup

Laboratory Evaluation

• Obtain complete blood count to assess for anemia from chronic bleeding 2, 3
• Order comprehensive metabolic panel to evaluate electrolyte abnormalities (particularly hypokalemic, hypochloremic metabolic alkalosis), renal function, and liver function 2, 3
• Check coagulation profile in preparation for potential surgical intervention 2

Imaging Studies

• Obtain CT scan with oral and IV contrast to determine the location and extent of obstruction, assess for metastatic disease, and evaluate resectability 1, 2, 3
• Plain abdominal radiographs have limited utility (50-60% diagnostic rate) but may be obtained as initial screening 2

Endoscopic Evaluation

• Perform upper endoscopy immediately to visualize the obstruction, obtain multiple biopsies to differentiate benign from malignant causes, and assess feasibility of endoscopic intervention 1, 2, 3
• Critical pitfall: Endoscopic biopsies have poor sensitivity (only 37%) for detecting malignancy in gastric outlet obstruction; even repeated jumbo biopsies can be falsely negative in 40% of gastric cancers 4
• Patients with benign endoscopic biopsies who are older (>55 years) or lack a history of peptic ulcer disease should undergo surgical exploration before committing to medical therapy, as they are at high risk for occult malignancy 4

Treatment Algorithm Based on Etiology

Malignant Gastric Outlet Obstruction

Resectable Disease

Surgical resection (distal or total gastrectomy with D2 lymphadenectomy) is the primary treatment for resectable gastric cancer with obstruction, as it provides the longest median symptom-free and overall survival compared to all other palliative methods 2, 3, 5

Unresectable Disease with Life Expectancy >2 Months and Good Functional Status

• Laparoscopic gastrojejunostomy is recommended as it provides lower blood loss, shorter hospital stay, more durable long-term symptom relief, and lower reintervention rates compared to endoscopic stenting 1, 2, 5
• EUS-guided gastrojejunostomy is an acceptable alternative to surgical gastrojejunostomy, providing similar long-lasting symptom relief with minimal invasiveness, depending on endoscopist expertise 2, 6, 7, 8

Unresectable Disease with Life Expectancy <2 Months or Poor Surgical Candidates

• Endoscopic placement of fully covered or partially covered self-expanding metal stents (SEMS) is preferred, providing faster oral intake resumption (typically within days), immediate symptom relief, and shorter hospital stay 9, 1, 2, 5
• Uncovered stents should never be used due to higher tumor ingrowth rates and inability to be removed 2
• Stent placement results in faster improvement in oral intake and symptom relief compared to surgery (P < 0.001) and shorter hospitalization (P < 0.001) 5

Absolute Contraindications to Enteral Stenting

• Multiple luminal obstructions—stents provide limited benefit 9, 2
• Severely impaired gastric motility 9, 2
• Perforation or peritonitis requiring emergency surgery 2

When Obstruction Cannot Be Alleviated or Bypassed

• Place a venting gastrostomy (percutaneous endoscopic, surgical, or interventional radiology approach) to reduce symptoms of obstruction 9, 2
• Critical pitfall: Drain ascites before venting gastrostomy tube placement to reduce the risk of infectious complications 9, 1, 2

Benign Gastric Outlet Obstruction

Endoscopic Management

• Perform balloon dilation as initial therapy 2
• If balloon dilation fails after multiple attempts (typically >4-6 sessions), place fully covered or partially covered SEMS for temporary use (4-8 weeks) to allow tissue remodeling 2
• Monitor for severe uncontrolled pain after stent placement, which requires immediate endoscopic stent removal 9, 2

Surgical Management

• Reserve surgical intervention for failed endoscopic approaches after multiple attempts, presence of complications, or anatomically unfavorable strictures 2
• Surgical options include conversion to Roux-en-Y gastric bypass for definitive treatment or stricturoplasty with seromyotomy to widen the narrowed segment 2
• Laparoscopic approach is preferred over open surgery when feasible 2

Nutritional Support

• If oral intake cannot be resumed within 5-7 days, provide nutritional support via jejunal feeding tube placed distal to the obstruction 1, 2
• For EGJ/gastric cardia obstruction, place feeding gastrostomy tubes; for mid and distal gastric obstruction, place jejunal feeding tubes if tumor location permits 9
• Critical pitfall: Never place feeding tubes distal to obstruction in cases requiring anatomic surgical correction (such as malrotation or diaphragmatic herniation), as these require definitive surgical repair, not nutritional bypass 1, 2
• Avoid overly aggressive enteral or parenteral nutrition in patients with very limited life expectancy, as this can increase suffering 1

Adjunctive Therapies for Malignant Obstruction

Bleeding Management

• Patients with acute severe bleeding (hematemesis or melena) should undergo prompt endoscopic assessment 9
• Endoscopic therapies (injection therapy, mechanical clips, argon plasma coagulation, or combination) may be initially effective, but recurrent bleeding rates are very high 9
• Angiographic embolization may be useful when endoscopy is not helpful 9
• External beam radiation therapy can effectively manage acute and chronic gastrointestinal bleeding 9

Systemic Therapy

• Chemotherapy improves survival in gastric cancer with gastric outlet obstruction and should be offered to patients with adequate performance status (KPS ≥60 or ECOG PS ≤2) 9, 5
• External beam radiation therapy and chemotherapy can be used to alleviate or bypass obstruction 9

Performance Status Considerations

• Patients with KPS score <60 or ECOG PS ≥3 should be offered best supportive care only 9
• Patients with better performance status (KPS ≥60 or ECOG PS ≤2) should be offered best supportive care with or without systemic therapy 9