What is the management and treatment of gastric outlet obstruction?

Gastric Outlet Obstruction: Comprehensive Management Guide

Definition and Clinical Presentation

Gastric outlet obstruction (GOO) is a mechanical blockage preventing gastric emptying, presenting with postprandial vomiting, epigastric pain, early satiety, and weight loss. 1

Key physical examination findings include:

• Abdominal distension and visible peristalsis 1
• Succussion splash (sloshing sound on abdominal palpation) 1
• Signs of dehydration and hypovolemic shock from persistent vomiting 1
• Digital rectal examination to detect occult blood or rectal mass if colorectal malignancy suspected 1

Etiology

Malignant Causes (Now Predominant)

• Antral gastric carcinoma (15% of all GOO cases, most common primary gastric malignancy) 2
• Pancreatic head cancer (one of two most frequent malignant causes, causing extrinsic duodenal compression) 2
• Gastric lymphoma (requires tissue diagnosis to differentiate from adenocarcinoma) 2
• Duodenal or ampullary neoplasms 2

Benign Causes (Historically More Common)

• Peptic ulcer disease (previously most common, now less frequent due to H. pylori eradication and PPI use) 3

Initial Diagnostic Workup

Laboratory Evaluation

• Complete blood count to assess anemia from chronic bleeding and leukocytosis 1, 2
• Comprehensive metabolic panel for electrolyte abnormalities (particularly hypochloremic hypokalemic metabolic alkalosis from vomiting) and renal function 1, 2
• Serum bicarbonate, arterial pH, and lactate to exclude intestinal ischemia 1, 2
• Coagulation profile in preparation for potential surgical intervention 1

Imaging Studies

• Abdominal plain X-ray as first-line study (50-60% diagnostic rate for small bowel obstruction) 1
• CT scan with oral and IV contrast is essential to determine location, cause, and extent of obstruction, assess for metastatic disease, and evaluate resectability 1, 2
• Water-soluble contrast studies have 96% sensitivity and 98% specificity for large bowel obstruction 1

Endoscopic Evaluation

• Upper endoscopy is mandatory to visualize the obstruction, obtain multiple biopsies for histologic diagnosis, and assess feasibility of endoscopic intervention 1, 2

Initial Supportive Management

All patients require immediate supportive care regardless of underlying etiology:

• Intravenous fluid resuscitation with isotonic crystalloids to correct dehydration and electrolyte abnormalities 1, 4
• Nasogastric tube placement for gastric decompression and prevention of aspiration pneumonia 1, 4
• Foley catheter insertion to monitor urine output 1
• Anti-emetics for symptom control 1, 4
• Bowel rest until obstruction is relieved 1, 4

Definitive Management Algorithm

For Malignant GOO

Resectable Disease

Surgical resection (distal or total gastrectomy with D2 lymphadenectomy) is the treatment of choice when curative resection is feasible. 4, 2 Neoadjuvant chemotherapy should be considered for locally advanced but potentially resectable disease. 2

Unresectable/Metastatic Disease with Life Expectancy >2 Months

Surgical gastrojejunostomy is preferred over stenting for patients who are surgically fit. 1, 4, 2

• Laparoscopic approach is preferred over open surgery when feasible 1
• Provides longer-lasting symptom relief compared to stenting 5, 6
• Median symptom-free survival is longest with palliative resection when feasible 5

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

Endoscopic self-expanding metal stent (SEMS) placement is recommended. 1, 4, 2

• Results in faster oral intake resumption (mean 6.9 days earlier than surgery) 7
• Shorter hospital stay (mean 11.8 days shorter than open gastrojejunostomy) 7
• Increased likelihood of tolerating oral intake (OR 2.6) compared to open gastrojejunostomy 7
• Use fully covered or partially covered SEMS to maintain luminal patency 1

For Benign GOO

Medical Management First-Line

• Proton pump inhibitors for peptic ulcer disease 3
• H. pylori eradication (strongly associated with successful relief without surgery) 3, 8
• Discontinue NSAIDs (continued use associated with recurrent obstruction) 8

Endoscopic Balloon Dilatation

• Initial success rate of 30% with single dilatation, but repeat procedures often needed 8
• Long-term success improved by H. pylori elimination and NSAID cessation 8
• Reserve for 4-8 weeks with temporary stent placement to allow tissue remodeling 1

Surgical Intervention for Benign Disease

Surgery is reserved for failed endoscopic approaches after multiple attempts (typically >4-6 sessions), presence of complications, or anatomically unfavorable strictures. 1

• Surgical gastrojejunostomy provides better technical success for benign GOO compared to EUS-guided gastroenterostomy 6
• Options include Roux-en-Y gastric bypass, stricturoplasty with seromyotomy 1

Special Situations and Contraindications

When NOT to Place Enteral Stents

Do not place enteral stents in patients with multiple luminal obstructions or severely impaired gastric motility due to limited benefit. 1, 2

• Consider venting gastrostomy for symptom relief instead 1, 2
• Drain ascites before venting gastrostomy placement to reduce infectious complications 9, 1, 2

Post-Stent Complications

Severe uncontrolled pain after gastric stent placement requires immediate endoscopic stent removal. 1, 2

Nutritional Support

• Feeding gastrostomy tubes for esophagogastric junction/gastric cardia obstruction 1
• Jejunal feeding tubes for distal gastric obstruction if oral intake cannot be resumed within 5-7 days 1
• Total parenteral nutrition can be considered to improve quality of life in patients with life expectancy of years to months 9

Prognostic Factors

Independent prognostic factors affecting survival include:

• Age and BMI 5
• Pre-procedure gastric outlet obstruction scoring system (GOOSS) 5
• Palliative resection as treatment modality (provides survival benefit) 5
• Receipt of chemotherapy (improves survival in gastric cancer with GOO) 5
• Poor nutritional status, ascites, and poor functional status predict surgical gastrojejunostomy failure 2

Critical Pitfalls to Avoid

• Do not use metoclopramide or other prokinetic antiemetics in complete obstruction (may be beneficial in partial obstruction only) 9
• Younger age, need for multiple endoscopic procedures, and long treatment duration predict eventual need for surgery in benign disease 8
• Clinical condition before treatment significantly affects survival and must guide treatment selection 5
• Abdominal pain before EUS-guided gastroenterostomy is a risk factor for technical failure 6