Achalasia

contributed by Dr Frank Gaillard on May 2, 2008

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Achalasia is a failure of organized peristalsis with relaxation at level of lower oesophageal sphincter

Etiology

a) Idiopathic: due to an abnormality of Auerbach plexus
b) Chagas disease

Peristalsis in the distal smooth muscle segment of the oesophagus may be lost. Contractions occur, but they are weak, simultaneous, uncoordinated and as a result nonpropulsive. The LES fails to relax, either partially or completely. LES pressure is elevated in some patients. The coordination of LES relaxation in response to swallowing and oesophageal contraction is lost.

Features

Dilatation of pesophagus beginning in upper 1/3 and eventually involving the entire length
Absence of primary peristalsis below level of cricopharyngeus
Nonperistaltic contractions
"bird-beak" / "rat tail deformity" is a conical symmetric tapering of stenotic segment with narrowing most marked at GE junction
Temporary transit through cardia when hydrostatic pressure of barium column is above tonic LES pressure
Numerous tertiary contractions in nondilated distal esophagus of early achalasia

Imaging

CXR

right convex opacity behind right heart border; occasionally left convex opacity if thoracic aorta tortuous
Air-fluid level (stasis in thoracic esophagus filled with retained secretions + alimentary residue)
small / absent gastric air bubble
anterior displacement + bowing of trachea on the lateral view.
patchy bilateral alveolar opacities resembling acute / chronic aspiration pneumonia

Fluroscopic studies

Failure of peristalsis to clear the oesophagus of barium when the patient is in the recumbent position
Uncoordinated, nonpropulsive, tertiary contractions
Oesophageal body dilatation, which is typically maximal in the distal esophagus
Pooling or stasis of barium in the oesophagus when the oesophagus has become atonic or noncontractile (late feature in the disease)
Incomplete LES relaxation that is not coordinated with oesophageal contraction
Bird beak sign