How should I evaluate a suspected hiatal hernia?

How to Check for Hiatal Hernia

Order a biphasic esophagram (barium swallow with double contrast) as the initial diagnostic test for suspected hiatal hernia, which achieves 88% sensitivity and provides both anatomic and functional information about the hernia, esophageal length, strictures, and reflux. 1, 2

Initial Diagnostic Approach

First-Line Imaging Study

• A biphasic esophagram combines double-contrast views with high-density barium suspension and single-contrast views with low-density barium suspension, optimizing detection of both inflammatory conditions and hiatal hernias 1
• The double-contrast phase optimizes detection of inflammatory conditions, while the single-contrast phase optimizes detection of hiatal hernias and esophageal rings/strictures 1
• This combined technique achieves higher sensitivity (88%) compared to single-contrast alone (77%) or double-contrast alone (80%) 1
• Alternative fluoroscopic studies include double-contrast upper GI series (80% sensitivity) or single-contrast esophagram (77% sensitivity), though these are less comprehensive 1, 2

Clinical Context Matters

• If the patient presents with typical GERD symptoms (heartburn, regurgitation) without alarm symptoms, you can initiate a 4-8 week PPI trial before imaging, as these symptoms are approximately 70% sensitive and specific for objective GERD 3
• Central obesity and/or a known hiatal hernia point to a mechanical etiology of gastroesophageal reflux 3
• Alarm symptoms requiring immediate objective testing include dysphagia, odynophagia, weight loss, anemia, or gastrointestinal bleeding 3

When to Use CT Scan Instead

CT is Reserved for Specific Scenarios

• CT scan with IV and oral contrast is the gold standard for diagnosing complicated diaphragmatic hernias, with 14-82% sensitivity and 87% specificity 3, 1, 2
• Use contrast-enhanced CT of chest and abdomen when: 3, 2
  • Clinical suspicion remains high despite inconclusive chest X-ray
  • Evaluating for complications (ischemia, strangulation, volvulus)
  • Trauma patients with suspected diaphragmatic injury
  • Post-bariatric surgery patients with suspected internal hernia

Critical CT Findings

• CT demonstrates diaphragmatic discontinuity, "collar sign," "dependent viscera" sign, and intrathoracic herniation of abdominal contents 3, 2
• CT findings of ischemia include absence of gastric wall contrast enhancement, intestinal wall thickening with target enhancement, and lack of enhancement after contrast injection 2
• CT is superior for determining presence, location, and size of diaphragmatic defects 3, 2

Alternative Diagnostic Methods

Endoscopy (Upper GI Endoscopy)

• Endoscopy can diagnose hiatal hernias greater than 2 cm in axial span 4, 5
• All patients being considered for antireflux surgery must undergo both barium esophagogram AND endoscopy to evaluate for esophagitis, strictures, Barrett's esophagus, and rule out complications 1, 6
• Endoscopy is less reliable for detecting subtle hernias less than 2 cm due to mobility of the esophagogastric junction 4, 5

High-Resolution Manometry

• High-resolution manometry is the most accurate method for detecting subtle hiatal hernias less than 2 cm by measuring real-time axial separation between the lower esophageal sphincter and crural diaphragm 4, 5
• Manometry is mandatory before any surgical intervention to evaluate esophageal peristaltic function and rule out achalasia 3, 6
• This test is typically reserved for patients being evaluated for surgery or those with refractory symptoms 3, 6

Chest X-Ray Limitations

• Chest X-ray has only 2-60% sensitivity for left-sided hernias and 17-33% for right-sided hernias 3, 2
• Normal chest radiographs occur in 11-62% of diaphragmatic hernias, making this an unreliable screening test 3, 2
• Suspicious findings include abnormal bowel gas pattern, air-fluid level, abnormal lucency, or hemidiaphragm elevation 3

Common Pitfalls to Avoid

Don't Make These Mistakes

• Never rely on chest X-ray alone to exclude hiatal hernia—proceed to biphasic esophagram if clinical suspicion persists despite normal X-ray 3, 2
• Don't order CT as first-line imaging for uncomplicated hiatal hernia when fluoroscopic studies are more appropriate and informative 2
• Don't use non-contrast CT when evaluating relationship between hernia and vascular structures—IV contrast is essential for detecting complications 2
• Never assume a hiatal hernia is uncomplicated without proper imaging—large hernias can contain stomach, colon, spleen, or other viscera (Type IV) 1

Special Populations

• In pregnant patients with suspected non-traumatic diaphragmatic hernia, use ultrasonography first, followed by MRI if necessary, to avoid radiation exposure 3, 2
• In stable trauma patients with lower chest penetrating wounds, diagnostic laparoscopy is recommended over imaging 3

Algorithmic Approach

1. Patient presents with suspected hiatal hernia symptoms (heartburn, regurgitation, dysphagia, chest pain)
2. Assess for alarm symptoms (dysphagia, weight loss, bleeding, anemia)
   • If alarm symptoms present → proceed directly to endoscopy AND biphasic esophagram 3, 1
   • If no alarm symptoms and typical GERD → consider 4-8 week PPI trial first 3
3. If PPI trial fails or objective testing needed → order biphasic esophagram as initial imaging 1, 2
4. If biphasic esophagram inconclusive but suspicion high → order contrast-enhanced CT chest/abdomen 3, 2
5. If considering surgery → complete preoperative workup with barium esophagogram, endoscopy, and high-resolution manometry 1, 6