What is the initial workup for a suspected hernia?

Initial Workup for Suspected Hernia

For suspected hernias, the initial workup should include a chest X-ray followed by CT scan with contrast enhancement if clinical suspicion remains high after initial imaging. 1

Diagnostic Approach by Hernia Type

General Approach

• Begin with a chest X-ray (both anteroposterior and lateral views) as the first diagnostic study for patients presenting with respiratory symptoms 1
• If clinical suspicion remains high despite normal chest X-ray findings, proceed to CT scan with contrast enhancement of the chest and abdomen 1
• CT scan is the gold standard for diagnosing hernias with sensitivity and specificity of 14-82% and 87%, respectively 1

Diaphragmatic Hernia

• Chest X-ray findings to look for include: abnormal bowel gas pattern, air-fluid level, abnormal lucency, soft tissue opacity with mediastinal deviation, or hemidiaphragm elevation 1
• For diagnostic enhancement, consider placing a nasogastric tube which can help identify herniated stomach on imaging 1
• CT scan findings indicative of diaphragmatic hernia include:
  • Diaphragmatic discontinuity
  • "Dangling diaphragm" sign (free edge of ruptured diaphragm curling toward abdomen center)
  • "Dependent viscera" sign (no space between liver/bowel/stomach and chest wall)
  • "Collar sign" (constriction of herniating organ at rupture level) 1

Hiatal Hernia

• For epigastric pain with suspected hiatal hernia, fluoroscopy studies are recommended as initial imaging 1
• Options include:
  • Fluoroscopy biphasic esophagram
  • Fluoroscopy single-contrast esophagram
  • Fluoroscopy upper GI series 1
• Double-contrast upper GI series is particularly useful for diagnosing hiatal hernia and provides information on esophageal length, strictures, and reflux 1

Inguinal Hernia

• Physical examination is usually sufficient for diagnosis - check for bulge or impulse while patient coughs or strains 2
• For athletes without palpable impulse or bulge, ultrasonography or MRI may help diagnose the hernia 2
• The inguinal occlusion test combined with hand-held Doppler device can accurately distinguish between direct and indirect inguinal hernias (79% accuracy for direct and 93% for indirect hernias) 3

Ventral/Abdominal Wall Hernias

• CT is particularly valuable when patients are obese or have had previous surgery 4
• CT can distinguish hernias from masses of the abdominal wall such as tumors, hematomas, abscesses, undescended testes, and aneurysms 4
• Consider patient characteristics when planning workup: BMI, body habitus, hernia reducibility, location, abdominal wall thickness, and defect size 5

Special Considerations

Pregnant Patients

• For pregnant patients with suspected non-traumatic diaphragmatic hernia:
  • Begin with ultrasonography as the first diagnostic study 1
  • If needed, follow with MRI after ultrasonography 1

Trauma Patients

• In stable trauma patients with suspected diaphragmatic hernia, CT scan with contrast enhancement is strongly recommended 1
• For stable trauma patients with lower chest penetrating wounds, diagnostic laparoscopy is recommended 1
• Endoscopy is not recommended for traumatic hernias 1

Common Pitfalls and Caveats

• Normal chest radiographs are reported in 11-62% of diaphragmatic injuries or uncomplicated diaphragmatic hernias 1
• CT scan may miss small tears from penetrating injuries like stab wounds when no hernia has yet occurred 1
• Intermittent herniation may appear normal on chest X-ray but can be detected on CT scan 1
• Contralateral hernias are often undiagnosed by physical examination alone (11.2% in one study), particularly in inguinal hernias 6
• Delayed presentation of diaphragmatic hernia is common and can be asymptomatic for decades before becoming symptomatic 1