Thoracoscopic and Laparoscopic Myotomy Laboratory Medicine

Updated: May 06, 2019
  • Author: Shabir Bhimji, MD, PhD; Chief Editor: Dale K Mueller, MD  more...
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Laboratory Medicine

Laboratory Medicine Summary

Contrast esophagography

The preferred initial diagnostic test for most patients who present with progressive dysphagia is contrast esophagography. This inexpensive and readily available study often reveals the classic findings of a dilated esophagus, impaired peristalsis, and the pathognomonic smooth tapering at the esophagogastric junction (EGJ) commonly termed "bird's beak" esophagus.

If diagnosed early, the esophagus may be of normal caliber, although most patients present with some element of dilatation. Commonly an air-fluid level forms as esophageal emptying is delayed, or the barium tablet or marshmallow "hangs up" just above the EGJ and may require several minutes to pass. Food particles are often seen despite patients' fasting for several hours prior to the study, indicating a significant delay in esophageal emptying. In long-standing achalasia, the esophagus can become dilated and tortuous and has been termed sigmoid-shaped or megaesophagus.


Manometry is essential in making the diagnosis, with the vast majority of patients exhibiting the classic findings of incomplete lower esophageal sphincter (LES) relaxation and aperistalsis of the esophageal body. [20] In a minority of patients, manometry tracings show simultaneous contractions, often of normal amplitude, which some have referred to as "vigorous achalasia." A common misconception is that the LES must also be hypertensive. Although the LES pressure can occasionally be elevated, most patients have normal LES pressures (< 45 mmHg) with incomplete LES relaxation with deglutition.


Endoscopy is necessary to exclude pseudoachalasia and to evaluate for atypical anatomy such as epiphrenic or traction diverticula. Characteristic endoscopic findings include a dilated esophagus with failure of the LES to open with insufflation and some mild resistance to passage of the scope through the EGJ, commonly described as a "pop." Retained food and debris in the esophagus are common. If suspicion of pseudoachalasia persists, endoscopic ultrasonography (US) with biopsy and computed tomography (CT) should be included in the evaluation.