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Diagnostic modalities of oesophageal disease

Investigations for gastroesophageal reflux disease

Many modalities may be used in gastroesophageal reflux disease:

Oesophageal pH monitoring

Oesophageal pH can be monitored by a probe or wireless capsule placed in the stomach near the lower oesophagus for 24 hours, allowing measurement of acid in the distal oesophagus.

Oesophageal impedance

Oesophageal impedance measures the flow of reflux into the oesophagus. It works on the principle of measuring impedance (resistance to electrical flow). It can measure reflux of gas and liquid, not only pH. It’s often measured simultaneously as pH monitoring detailed above with the same device.

Bilitec

Bilitec® detects bilirubin in the oesophagus and is a test for biliary reflux.

Investigations for oesophageal motility disorders

These investigations are used for the diagnosis of oesophageal motility disorders like achalasia or diffuse oesophageal spasm.

  • Oesophageal manometry
  • Barium swallow

Oesophageal manometry

Manometry is the gold standard for diagnosis of motility disorders. It uses a transnasal catheter with pressure sensors to analyse pressure at different points in the oesophagus, allowing analysis of the peristaltic waves in the oesophagus.

Barium swallow

Barium swallow, also called an oesophagogram, involves making the patient swallow barium contrast while the oesophagus is imaged by fluoroscopy. This allows visualisation of food moving through the oesophagus in real time. A "filling defect" on the barium swallow, defined as a portion of the oesophagus which isn't filled by the barium contrast, can be due to:

A double-contrast oesophagogram refers to when barium is swallowed first, then air or CO2 releasing tablets.

Barium is contraindicated in

  • Suspicion of perforation of GI tract
  • After GI surgery
  • High risk for aspiration

If barium is contraindicated, gastrographin is used instead. It is a water-soluble, iodinated contrast agent. Barium leak can cause necrotizing peritonitis.

Investigations for oesophageal cancer

The diagnosis of oesophageal cancer is histologic, and a biopsy is obtained by upper endoscopy (oesophagoscopy).

CT and PET-CT are also important in the evaluation of oesophageal cancer but somewhat out of the scope of the topic.