The caged bird sign of achalasia: A case series describing a new radiologic sign that can be reliably used in a resource-poor setting to diagnose achalasia.

Introduction: Achalasia is an uncommon oesophageal motility disorder caused by failed relaxation of a hypertensive lower oesophageal sphincter in response to swallowing. It often manifests clinically with symptoms such as dysphagia, regurgitation, and weight loss. Manometry is considered the gold standard diagnostic test in diagnosing this condition. However, it is not always accessible, especially in the resource-limited setting. Other radiological adjuncts, such as barium oesophagram, often show features that are highly suggestive of achalasia: the bird-beak appearance of the distal oesophagus, and a dilated oesophagus (megaoesophagus) containing food residue, which may then progress to become tortuous (sigmoid) or aperistaltic. Thus, the use of these tests play a significant role in the identification of this condition.

Case Presentation: Three patients were diagnosed with achalasia at the San Fernando General Hospital, Trinidad and Tobago. Together with characteristic symptoms, barium oesophagrams demonstrated features of achalasia, bearing a close resemblance to those of a caged bird. The barium oesophagrams were scrutinized by a fellowship trained, upper GI advanced laparoscopic surgeon, and the consistent features described were noted.

Conclusion: In the setting where manometry is not accessible, barium oesophagram plays an important role. We propose that recognition of easily identifiable features such as the "caged bird sign of achalasia" on this imaging modality can assist in the diagnosis of this entity.