Hiatal Hernia Diagnosis
The recommended initial diagnostic test for hiatal hernia is a biphasic esophagram (combining double-contrast and single-contrast barium studies), which achieves 88% sensitivity and provides both anatomic and functional information about the esophagogastric junction. 1
Primary Diagnostic Approach
Start with fluoroscopic barium studies as first-line imaging:
Biphasic esophagram is superior to single imaging techniques, combining double-contrast views (optimized for detecting inflammatory conditions and mucosal abnormalities) with single-contrast views (optimized for detecting hiatal hernias, esophageal rings, and strictures). 1
The combined technique achieves 88% sensitivity compared to 77% for single-contrast alone or 80% for double-contrast alone. 1
Double-contrast upper GI series specifically detects hiatal hernia presence and size, evaluates esophageal length, identifies strictures, and assesses for gastroesophageal reflux and reflux esophagitis. 2
For large hiatal hernias, ensure the upper GI series includes complete stomach evaluation. 2
When to Use CT Imaging
CT scan should be reserved for specific clinical scenarios, not as first-line imaging:
Use contrast-enhanced CT (chest and abdomen with IV contrast) when chest X-ray findings are inconclusive but clinical suspicion remains high, or when evaluating for complications. 1
CT is the gold standard for complicated diaphragmatic hernias with 87% specificity, demonstrating diaphragmatic discontinuity, intrathoracic herniation of abdominal contents, and complications of herniated organs. 1, 2
Critical pitfall to avoid: Do not order CT as first-line imaging when fluoroscopic studies are more appropriate and informative for uncomplicated hiatal hernia diagnosis. 2
Complementary Diagnostic Studies
All patients being considered for antireflux surgery require:
Barium esophagram (as recommended by the American College of Surgeons' Esophageal Diagnostic Advisory Panel). 1
Esophagogastroscopy to evaluate for erosive esophagitis, esophageal strictures, and differentiate other pathologies like eosinophilic esophagitis. 3, 4
Esophageal manometry to assess motility and confirm diagnosis. 4
Classification Context for Diagnosis
Understanding hiatal hernia types guides diagnostic interpretation:
Type I (sliding hernia, 90% of cases): Gastroesophageal junction migrates above the diaphragm through widened esophageal hiatus. 5
Type II (paraesophageal, 10%): Gastric fundus herniates while gastroesophageal junction remains in normal position. 5
Type III: Combined Type I and II with displaced gastroesophageal junction. 5
Type IV: Large defect accommodating stomach, colon, spleen, or other viscera. 5
The distinction between sliding and paraesophageal hernias is crucial as surgical approaches differ significantly. 3
Special Population Considerations
For pregnant patients with suspected non-traumatic diaphragmatic hernia:
- Use ultrasonography as first diagnostic study, followed by MRI if necessary to avoid radiation exposure. 2
Common Diagnostic Pitfalls
Normal chest radiographs occur in 11-62% of diaphragmatic hernias, so negative plain films do not exclude the diagnosis. 1, 2
Hiatal hernias less than 2 cm are difficult to diagnose with any modality and may require multiple complementary studies. 6
Non-contrast CT provides limited assessment of vascular structures and potential complications like ischemia or strangulation, particularly when evaluating retrocardiac hiatal hernias. 2